NOISE
PREDICTION TECHNIQUES
FOR HIGHWAY
DESIGN
by
MOHAMMAD ASHRAF
B.E.
(C.E.),
N.E.D.
JAN
Engineering College,
Karachi,
Pakistan
(1959)
M.S.
(C.E.),
Virginia Polytechnic
Institute
(1962)
SUBMITTED
OF
THE
IN
PARTIAL FULFILLMENT
REQUIREMENTS
DEGREE
OF MASTER
CITY
FOR
THE
IN
PLANNING
at
the
MASSACHUSETTS
INSTITUTE
OF
TECHNOLOGY
February,
Signature
of Author
1970
5
Department of
Urban
U
Studies and
September
Planning
23, 1969
Certified by
Thesis
Accepted
Supervksors
by
Chairman,
Rotch
pss.
INST.
TEC.
MAR 1 8 1970
-tpartmental
Committee
on Graduate Students
ii
Noise Prediction Techniques for Highway Design
Mohammad Ashraf Jan
Submitted to the Department of Urban Studies and Planning
on September 23,
requirement
1969,
for the
in the partial
degree
of Master
fulfillment of the
of
City Planning.
This study is an attempt to explore and develop techniques for prediction of noise effects of freeways, and
However, 'noise
their incorporation in highway design.
impacts
environmental
array
of
in
an
but
one,
is
effects'
We
of highways about which there is a growing concern.
of
genconsequences
the
predict
to
techniques
need such
erated designs, before the consequences could be evaluated.
It was hypothesized, that if relationships between
and (b)
levels,
and noise
(a)
highway design variables
people's reaction to noise levels, could be established
and organized, then the designer could exercise control
over the noise effects of highways.
Further literature review revealed that Bolt Beranek
and Newman, Inc., have investigated these relationships
in their Report No. 1505, under the N.C.H.R.P. program for
the Highway Research Board.
It was decided then:
(1)
To understand these relationships in the framework of a
rela(2)
OrQganize these
highway design process,
broader
tionships for development of noise contours to study
simultaneously noise effects on all land uses in highway
corridor, rather than acoustic analysis of one particular spot, (3) Demonstrate the noise contour development
process, through a Case Study of 1-93 design in metropolitan Boston.
Through
the
noise
contour
development process
a
framework is laid which could serve as a basis for highway
location design in a corridor of already developed land
uses, as well as, for a system of land use planning in the
new
joint
development
corridors.
The comparison of alternate designsin this framework
is perhaps more objective in relative than absolute terms
at present, due to lack of information regarding people's
reaction to noise levels, and attenuation effects of
With better
intervening structures and topography.
knowledge in these areas the objectivity of noise prediction techniques is anticipated to increase.
Joint
Thesis Supervisors:
John Tasker Howard
Title:
Professor of City Planning, Head of the Department
Richard Lawrence deNeufville
Assistant Professor of Civil Engineering
Title:
To The
Memory
Of Dear Masud
iv
ACKNOWLEDGEMENTS
This
research has
assistantship
search
to
under
Program of
express my
been partly
the
the
National
Highway
gratitude
for
I am deeply grateful
in this
research.
Professor
John T.
Howard,
gate
the
'noise effects
throughout
this
I
for his
penetrating
work.
am sincerely
models'
and
profound gratitude to
and his
to
investi-
kind guidance
my educational program at
grateful
to Dr.
Richard L.
criticism and genuine
the
I wish
people who have
L.
concept
Manheim
I
am indebted for
and role of
in initiating this
'prediction
and his helpful
research.
Professor Aaron Fleisher for his
deNeufville,
interest in my
in the problem solving processes,
suggestions
to
to
and
Re-
support.
several
My
a research
Highway
for his encouragement
To Professor Marvin
introducing me
this
of highways,'
research
M.I.T.
Co-operative
Research Board,
to
guided me
supported by
My thanks
help,
are due
and allowing
me
encroach upon his time whenever I needed him.
Special gratitude
Cavanaugh
helpful
Library.
valuable
various
any
of
the
form without
presented
to
The
to Mr.
and Newman
and allowing me
I want
discussions.
reports
expressed
Bolt Beranek
suggestions,
Also,
is
the
Inc.,
use
thank Mr. James
data and
here
the permission
of
J.
tables
should
not
BBN
William
of
for his
BBN
Coles
for his
from their
be
Inc.
reproduced
in
to
V
My warmest
appreciation
is
due
Rogers
of
the
Charles
lowing
to
use
their preliminary plan
'base map'
This
for the
plan, however,
permission of
N.C.H.R.P.
A.
Maguire
I would like
at M.I.T.,
to
in the
in
for
Cranston R.
Inc.
1-93,
alternates in
should not be
project, and
and Planning
Maguire Associates
hypothetical
Charles
Finally,
A.
to Mr.
for al-
as
this
a
study.
reproduced without
Associates
Inc.
thank my colleagues
Department
particular Mr.
of
the
in the
Urban Studies
William Sims.
vi
TABLE
OF
CONTENTS
Page
No.
Abstract
Acknowledgments
List of Figures
List
of Tables
.
.
. . 1
CHAPTER I.
INTRODUCTION
.
.
.
PART
NOISE PREDICTION TECHNIQUES -DEVELOPMENT OF NOISE CONTOURS.
.
.
8
NEED FOR PREDICTION TECHNIQUES
IN THE HIGHWAY LOCATION DESIGN
PROCESS. . . . . . . . . . . .
.
.
9
.
.
9
ONE:
CHAPTER II.
.
.
.
.
.
.
.
.
.
A.
Definitions.
B.
Need for a Broader Highway
.
.
.
.
Location Design Process, and
Place of Prediction Techniques
CHAPTER
III.
.
.
.
.
16
VEHICLE NOISE MEASUREMENT -SELECTION OF A MEASURE . . .
.
.
.
25
A.
B.
Noise
Parameters.
25
......
Selection of a Vehicle Noise
Measure.
CHAPTER IV.
.
.
in Such a Process.
.
.
.
.
.
.
.
.
.
.
PREDICTION OF NOISE FROM HIGHWAY
DESIGN VARIABLES . . . . . . . .
A.
Sources
B.
Variables in Vehicle Noise
Generation . . . . . . . .
C.
The
of
.
29
.
36
36
Traffic Noise..
Estimation of
Noise Levels
..
.
.
38
.
.
39
Traffic
.
.
.
.
.
vii
Page
CHAPTER V.
NOISE POLLUTION--PEOPLE'S REACTION
TO NOISE FROM FREEWAYS . . . . . .
A.
B.
C.
CHAPTER VI.
Nature of the Problem and
Implications . . . . . . .
Approximate Noise Levels
Various Land Uses. . . .
Ambient Noise.
.
.
.
.
.
.
.
69
for
. .
.
73
.
.
78
.
NOISE PREDICTION PROCESS
DEVELOPMENT OF NOISE CONTOURS.
Phase-A:
Establishment of
Goals. . . . . .
Phase-B:
Phase-C:
81
Noise
. . .
.
81
Development of
Contours . . .
Noise
. . .
.
84
Noise Severity
trol Analysis.
and Con. .. . . .
91
.
Summary
PART
TWO:
CHAPTER VII.
69
100
CASE
STUDY
.
.
.
.
.
.
.
.
.
.
.
.
.102
CASE
STUDY
.
.
.. .
.
.
.
.
.
.
.
.
.106
A.
B.
Project Location and
Descrip-
tion.
......
...
. .
.
Noise Prediction and
Development Process.
1.
Phase-A:
Contour
. . . .
.106
.
.107
Establishment of
Noise Goals . . .
.107
a.
Quadrant-B
.
.
.
.
b.
Quadrant-C
.
.
.
. ...
c.
Quadrant-A
.
.
.
.
.
.
.
.108
110
.
41.
.114
No.
Viii
Page
2.
3.
CHAPTER VIII
REFERENCES
Phase-B:
Development of
Noise Contours
a.
Quadrants
b.
Quadrant-A
Phase-C:
B
and C.
.
.
.
.
No.
.
.
.
115
.
.
.
.
116
.
.
.
. 128
Noise Severity and
Control Analysis .
.
131
a.
Quadrant-B
.
.
.
.
.
.
.
. 141
b.
Quadrant-C
.
.
.
.
.
.
.
. 147
C.
Quadrant-A
.
.
.
.
.
.
.
. 155
d.
Conclusions for Case
Alternates . . . . .
CONCLUSIONS.
AND NOTES . . .
.
.
. .
.
.
.
. ..
.-
.
.--...-.
Study
. . . 158
162
170
ix
LIST OF FIGURES
No.
FIG.
Title
II-1
P age
Role of Prediction Models in
Design Process . . . . . . .
the
. .
.
.
13
.
FIG.
11-2
Basic
.
.
.
15
FIG.
IV-l
Typical Free-Flowing Automotive
Traffic Noise Spectra. . . . . .
.
.
37
Key Variables Influencing Barrier
Attenuation of Sound . . . . ...
.
.
49
Sound Attenuation as Function of Fre
quency and Barrier Height, for the
Case Shown . . . . . . . . . . . . .
49
Sound Attenuation by Different Depressed Roadways Configurations,
Equal to the Side-Wall . . . . . .
51
FIG.
FIG.
FIG.
FIG.
IV-2
IV-3
IV-4
IV-5
Problem Solving
Module
.
Sound Attenuation Effects of Reflecting and Sloping Side-Walls.
53
FIG.
IV-6
Noise Reduction Provided by Various
Highway Configurations . . . . . . .
FIG.
IV-7
Effects of Topography.
FIG.
VI-1
Noise Prediction
PLAN-1
Location
PLAN-2
1-93 Project
Goals. . . .
.
.
.
.
.
.
.
57
62
Format.
.
.
.
.
.
.
85
.
.
.
.
.
.
.
103
Plan, Land Uses, Noise
. . . . . . . . . .. . .
104
Plan.
.
.
.
.
FIG.
VII-l
Grade
.
.
.
.
.
.
. 105
FIG.
VII-2
Quadrant-B cross-section
.
.
.
.
.
. 143
FIG.
VII-3
Line of Sight Analysis
(School, Church).. . . .
.
.
.
. ..
ALT-I, Quadrants: B & C
Noise Contours from Mainline
Traffic. . . .
. . . .
. .
.
.
MAP-1
Profiles
.
.
.
.
.
144
.
118
No.
x
No.
Title
MAP-2
ALT-I, Quadrants: B & C
Superimposed Noise Contours from
Y-Line Traffic . . . . . . . . .
MAP-3
MAP-4
:
:
Page
.
.
No.
.121
ALT-I, Quadrants: B & C
Resultant Noise Contours
and Y-Line Traffic . . .
from Mainline
. . . . . . .122
ALT-II, Quadrants: B & C
Resultant Noise Contours
and Y-Line Traffic . . .
from Mainline
. . . . . . .127
MAP-5
:
ALT-III, Quadrants: B & C
Resultant Noise Contours from Mainline
and Y-Line Traffic . . . . . . . . . .130
MAP-6
:
ALT-I, Quadrant: A
Noise Contours from Mainline & Mystic
Av. N.B. & Ramps Configuration and
Middlesex Av. Traffic. . . . . . . . .136
MAP-7
:
ALT-I, Quadrant: A
Resultant Noise Contours from Mainline
& Mystic Av. N.B. & Ramps Configuration
and Middlesex Ave.Traffic. . . . . . .137
MAP-d
:
ALT-1, Quadrant: A
Superimposed Noise Contours from
Y-Line Traffic . . . . . . . . .
MAP-9
:
.
.
.138
ALT-I, Quadrant: A
Resultant Noise Contours from Mainline
& Mystic Ave.N.B. & Ramps Configuration
& Middlesex Ave., and Y-Line Traffic. -139
xi
LIST OF
No.
Table
Table
TABLES
Page
Title
IV-1
IV-2
Approximate Mean Noise Level (dBA),
of
a Straight,
to the side
100 ft.
Level Roadway as a Function of
Speed and Quantity of Traffic for
Mixed Traffic of 95% Autos and
5% Trucks . . . . . . . . . . . . . .
41
Noise Level Corrections for Distances Greater than 100 ft. to
Roadway . . . . . . . . . . . . .
. .
43
.
44
Table
IV-3
Truck Volume
Table
IV-4
Corrections for Upgrade and Acceleration . . . . . . . . . . . . . . .
Table
IV-5
No.
Noise Level
Attenuation
Corrections.
.
.
.
.
.
46
Reduction due to Various
Structures Between Road-
way and Point of
Interest
.
.
.
.
.
.
55
Table
IV-6
Noise Level Corrections for Exposure
to Partial Section of Roadway, Approximately centered with respect to point
64
of observation. . . . . . . . . . . .6
Table
IV-7
Pseudo
Lane
Location . . .
. .
. .
. .
67
Table
IV-8
Addition of
Decibels . . .
. .
. .
.
67
Table
V-1-A
Approximate Nighttime Background Noise
Levels for Residential Areas . . . . .
Table
V-l-B
Approximate
Desired Background
Table
V-2
VI-1
.
Estimate of Outdoor Background Noise
Based on General Type of Community
Area and Nearby Automotive Traffic
Activity. . . . . . . . . . . . . . .
Significance
of Noise
Level
76
Noise
Levels in Non-Residential Buildings
Table
.
Excesses.
77
79
92
CHAPTER-I
Introduction
This
niques
would
sign
study
attempt
to
explore and
for prediction of "noise effects"
include
investigation of
features
grade
is an
of
elevation,
people's
freeways
etc.)
reaction
With
availability
tion
in
that
freeways
the
of
be
levels
noise
of freeways.
This
between de-
volume,
on
one
levels on
techniques,
highway design
could
traffic
and noise
such
tech-
relationships
(e.g.,
to various
develop
process,
and
it
is
speed,
hand,
the
their
and
other.
incorpora-
anticipated
designed with better control
over
thier noise pollution impacts.
However, noise
environmental
mounting
ties
in
urban
urban
York,
have
pacts
of
of the
several
The
"Interstate
to the
of highways
road,
of
Highway
in the
on
tax base
1
of
a series of
about which
protests
New
surface,
Air pollution,
loss
but one
there
interest groups
Chicago,
such intervention
communities.
is
highways
areas.
Boston,
brought
intervention
of
among
segments of
like New
cisco
impacts
concern
the
effects
System"
the
environmental
San Fran-
services,
and
the
values of
noise pollution,
to
in cities
concern about
fabric,
a
communi-
and opposition
Orleans and
urban
and
and
is
the
imurban
ugly-view
ugly view
from the
the
road, and community disruption are
included in
environmental impacts of highways, which are being
emphasized for consideration in design of highway facilities.
In this study we will
fects"
and techniques for its control.
investigate only
envisaged that these techniques will be
"noise ef-
However,
it is
considered in the
context of overall highway design process, and prediction
techniques
goals of
are needed also
communities.
for the other environmental
The ultimate goal of
such predic-
tion techniques would be to provide a broader framework
of trade-off analysis,
which in turn should lead to better
control over the environmental impacts of highways, and also
design of highway facilities
in harmony with the
fabric which surrounds them.
We shall
discuss in more
detail the need for such prediction techniques,
broader framework of highway design process,
chapter, and switch our focus
urban
in the
in the next
now on "noise effects", which
is the main concern of this research.
There is an ever increasing concern over traffic noise
in urban areas.
major noise study
The Wilson Committee which undertook a
in England, in 1963,
84 percent of 400 observed locations
miles of Central London, noise
dominated.
concluded that at
spaced over 36 square
from road traffic pre-
The Greater London Council's
*These numbers refer to the sources
list.
research also
in the
reference
confirmed
the predominance
by reporting
that at
of traffic noise
80 percent of
sites
in urban
areas,
measured, traffic
produced a higher level of noise than any other source. (2)
In the
United
Bolt-Beranek
and
States,
an urban
and Newman
Urban Development,
Angeles,
source".(3)
noise
lends
very
inviting
"automotive
traffic
is
the highest
of noise
(this is
community
etc.)
organized
in
not
noise
uses,
felt that traffic
techniques
to
imply
if
that more
less
volume,
levels
could be
way
tables
in
employ them
appeared
urgent).
relationships
(such as
and
complex im-
between
speed, grade,
established,
and
charts,
to predict
the
And the designer could use them as readily
say
tables
super-elevation
charts
or speed
from highway design manuals.
relationship
could be
could
ranking conscious
and
the
traffic
levels at all activity locations in the highway cor-
ridor.
able
a systematic
could
seen to be
measurement readily.
disruption are
and noise
designer
Los
the highway design process
variables
distance,
highway
it was
prediction
It was.hypothesized that
highway design
Department of Housing
and
itself to quantitative
incorporation in
like
the
conducted by
Boston,
Furthermore,
investigation
pacts
for
survey
New York,
(but not always)
noise
their
in
concluded that
generally
Thus
Inc.
noise
between people's
established,
noise
levels
then predict
for various
the
and curvature
In addition,
reaction and
and organized
as
consequences
of
noise
guides
land uses,
as he
the
design
for
if
levels
accept-
designer
alternatives
as
he
generates
increased
lead
them,
sensitivity
in
of the
to better control
Further
Bolt
tensively
ships
in
the
their
their
designer
in
noise
(BBN)*
studies
in
in
Co-operative
Highway Research Program,
and
of highways.
revealed
has
their
Report No.
1505,
This
should
that
investigated
and highway design variable
freeway noise
Board.
impact.
turn,
impacts
particularly
search
noise
noise literature
Newman Inc.,
noise
of
over the
review of
Beranek and
terms
ex-
relation-
recent years,
under
for
the
the National
Highway Re-
Their data is based on extensive
field
simulation studies over a period of several years.
Their recommendations
of highway
estimate
design,
noise
freeway. (5)
and
levels
We
in
into
traffic
consideration a wide
composition
at a particular
this
developing techniques,
generated
take
study,
on all land uses
them.
of
predicted
in the highway corridor.
contour
for
analogous
drainage
purposes
manipulation of grades
Newman
to
or
side
the
slopes,
*BBN is used as abbreviation
Inc., in this study.
for
To be more
"noise
as we generate
grading
route.
a highway
Bolt
in
simultaneously
development of
along
the
levels from
for studying
alternate highway designs,
This may be
to
are interested
through which noise
specific, developing noise contours
environment"
location along
however,
highway design could be
features,
range
Through
designer
Beranek and
5
achieves
a
desired drainage
face water
tours,
along
from
refinement
to
the
pattern, for
freeway.
the preliminary
to
drainage
final
implication of
for
the
designer to noise
the
influence
of
serve
corridor of
lines
to
sensitizes
corridor,
impacts on
all
the
as
could
as
a guide
already
the
he
for highway
developed
designer
develops
noise
sensitize
"actors"
a generated hiqhway design.
under
This
could
location design
land uses,
con-
successive
Similarly developing
entire highway
the
very well
lines,
sur-
of drainage
design variables,
alternate highway designs.
contours
Development
irregular
"flowing"
channelizing
as well
as
in a
a guide
for a system of land use planning in the highway corridor.
Such noise
niques
prediction techniques
for other
environmental values) ,
operationalization
ple
Use
in more
of
(along with prediction tech-
of
"Joint Development"
Highway-Right-of-Way.
detail
later.
In
view of
the
following objectives are
1.
In
depth
are
set
We
the
for
essential
concept
shall
and Multi-
discuss
previous noise
the
for
these
studies,
present research:
study of the relationships between,
a)
noise levels and highway design variables, and
b)
noise levels and people's reaction,
to
understand
as
to how
their implications
trade-offs
are
analysis,
those needed
in
these
for
were
a broader
framework of
highway design
for Joint Development
Planning projects.
derived, and what
process,
and Corridor
like
6
2.
Organizing these relationships for developing noise
contours,
through which
sign
alternate
land
uses within
performing
In
noise
trade-off
study,
the
in
all
than
spot.
"environmental" noise
the
through which
context of
thus providing
other
a broader
analysis.
noise prediction
techniques
to refine the prediction guides,
understanding of
involved.
is
on
Study:
Application of
the
highway de-
for one particular
studies
actors,
a
simultaneously
design process,
could be
of
corridor, rather
incorporating
various
framework of
Case
analysis
in the highway
effects
impacts
studies
the highway
acoustic
impacts on
3.
could be
other words,
study,
noise
Interstate
selected
relationships,
93
design
for the Case
Study.
to
a
case
and enhance
and
trade-offs
in metropolitan Boston
Following is an outline of the research program:
The
study
deals
with
which
led
analyze
the
the
to
the
overall
prediction
noise
is
for
into two major parts.
development of
need
"noise contours".
and place of
techniques
are
in the
proper
to place
noise
between highway
techniques,
First we
the
noise
perspective.
Then
defined and selection
highway traffic
One
"prediction techniques"
highway design process,
relationships
Part
investigation of noise prediction
parameters
measure
divided
is
of
an acceptable
discussed.
design variables
in
Next
and noise
7
levels are analyzed, followed by investigation of peoples'
reaction to various noise
are
levels.
These investigations
then synthesized into noise prediction and noise con-
tour development process, which could be
the overall highway design process.
incorporated in
Various noise con-
trol measures are also analyzed for thier incorporation
into alternate highway schemes, and study of the trade-offs.
Part Two comprises of a Case
Study.
The noise pre-
diction techniques organizedin Part One are applied to
Interstate-93 location design in metropolitan Boston.
This
resulted in further refinement of noise prediction techniques and procedures
The
in context of the real world situations.
study will conclude with summary recommendations and
evaluation of the contribution of the work done.
8
PART ONE
NOISE
PREDICTION TECHNIQUES --
DEVELOPMENT
OF NOISE
CONTOURS
CHAPTER
II
Need For Prediction Techniques In
The Highway Location Design Process:
As
stated
development of
limited to
corporate
in
the
freeway
control
the
introduction, our motivation
noise
prediction techniques
noise
impacts
such prediction
design process, for better
pacts of highways.
techniques
for other
could
emerge
of
a broader
its
for
highway
define
this
A.
overall
the
a
in-
highway
im-
envisaged that noise prediction
and
trade-off of
techniques
form the
analysis, through
highway design process with better
noise pollution
which
control
being one
impacts.
In
place
in
not
want to
control over environmental
environmental impacts;
these
we
relevant environmental goals, should
of
is
alone;
in concert with prediction models
basis
over
It is
techniques
for
this chapter we
shall
such prediction models
analyze the
need and
and techniques, in the
location design problem.
Moreover, we shall also
some of the terms which would be
used frequently in
study.
DEFINITIONS:
We
which
need prediction models
a
freeway
designer
and
could
techniques,
relate,
ic way, the highway design variables,
9
in a
through
systemat-
to the goal
10
variables of
the impacted
interest groups.
Let us first define goal variables, design variables,
and prediction models, to view their
relationships
in a clear perspective.
These
definitions are based on Manheim's proposal for a
study under National Cooperative Highway Research
Program. (1)
1.
Goal Variables:
Goal variables describe
specific
environmental values, whether of individual group,
neighborhood or broad community interest, which
may potentially be
design.
affected by highway
Goal variables may be grouped
ety of ways; by type,
location
in a vari-
by interest group,
affected
actor, etc.
Examples:
a.
(by interest group)
Highway User:
a.l.
Trip Time
a.2.
Trip Cost
a.3.
Comfort and Convenience of Ride
a.4.
Safety
a.5.
View from the Road
b.
Local Community:
b.l.
Safety
b.2.
Preservation of Historical and Cultural
Sites
ll
b.3.
Preservation
b.4.
Noise Effects
b.5.
Air
b.6.
Relocation of
b.7.
Highway
c.
of Natural
Beauty
Pollution
as
Persons
Barrier
and Businesses
in Community
Community:
Metropolitan
Preservation of Historical and Cultural
c.l.
Sites
c.2.
Air Pollution
c.3.
Effect
c.4.
Effect on
on Economic
Regional
Activity Location
Transport
and Modal
Split
Capital and Operating Costs of the Highway
c.5.
2.
Design Variables:
aspects
of
manipulated
Design variables
a highway
those
location design which
to potentially
sired environment
are
achieve
a set of
can be
de-
effects.
Examples:
a.
Alignment -
b.
Profile -
horizontal,
surface, elevated, depressed or
tunnel
c.
vertical
Cross-section
12
3.
d.
Access -
e.
Traffic control systems and policies
f.
Air rights construction techniques
partial, limited
Prediction Models:
anticipate
A
prediction model
some of the consequences
is used to
of a highway
location design, described in terms of the design variables.
Examples:
a.
Prediction of visual
Development
Impacts of Highway
a.l.
View from the Road
a.2.
View of the Road
b.
Prediction of Noise Effects of Highway
Traffic
c.
Prediction of Air Pollution from Highway
Traffic
d.
Prediction of the Impacts of the Relocation of Residences and Businesses
e.
Prediction of
Structure
f.
Prediction of the Distribution of Economic
Impacts
g.
Prediction of Construction Cost Quantities
Earthwork, Pavement, Structures, etc.
Impact on Neighborhood
-
13
GOAL
DESIGN
VARIABLES
VARIABLES
PREDICTION MODELS
I
I
I
I
VIcG. II- 1
ROLE-! OF PREDICTION MODELJ 1IN TIHE DESIGN . PROCE4S
14
We need such prediction models to predict
systematically the consequences of alternate
designs generated, and to test and verify the
prediction techniques,
so that these could be
repeated in future design.
It is hoped that
through prediction models,
the consequences of
design variables can be
related to goal variables
such that for each design variable
variables
(gi,2, ... ,n)
In this
II-1.
goal
impacted by its conseillustrated in
quences, can be specified as
Fig.
(di),
kind of analysis
it is
important and operationally useful to distinguish
between prediction of the consequences of highway location design
consequences.
(4)
from evaluation of the
These are
ferent kinds of tasks
process.
two basically dif-
in an engineering
First, there is
the
design
following problem:
given a particular statement of the design variables
design
that is,
-
-
a particular highway location
to be able
to predict all the conse-
quences that the design will have on its
environment.
Once the consequences of a
particular design alternative have been predicted, there is a separable problem of
evaluating those consequences
a statement about the
in order to make
relative desirability of
Alternative
Actions
SELECTION
Preferred
Action
H
Alternati
Action
sequence
Action
FIGURE
11-2.
BASIC
(Source:
Valuations
of
onsequences
PROBLEM-SOLVING MODULE
Manheim
(5)
)
CHOICE
Preferre
Action
16
one -design compared
to
another.
problem of evaluation:
of
several
sequences
a way
which alternate
trates
B.
is
the
given the consequences
alternatives, to
in
This
evaluate
that leads
to
is preferred.
a
those
con-
statement of
Fig.
11-2
illus-
solving module.(5)
the basic problem
NEED FOR A BROADER HIGHWAY LOCATION DESIGN PROCESS, AND
PLACE OF PREDICTION TECHNIQUES IN SUCH A PROCESS:
From the above listing of goal variables,
it is evi-
dent that impacts of a highway upon environmental values
are
felt at various levels and by different groups such
as road user, local neighborhood, and metropolitan community;
some
adversely
groups may benefit, while
affected.
controversy
it has
However,
in
the
current
the
been voiced that
others
may be
highway
conventional
highway location and design procedures consider only a
It has been argued that evalu-
narrow band of interest.
ation of alternate highway designs
efficiency for road users
in terms of economic
alone, as measured by the
"Road Users Benefit Analyses",( 6 ) has the misleading
advantage of simplicity.
(7)
The
selection in rural areas, where
scarce
grossly
and
criteria for route
social values are
engineering considerations paramount,
inadequate
for urban highway
locations;
are
due
to
application of this narrow criteria urban expressways
are
increasingly being
regarded as
responsive to public values. (8)
a
tyrant,
and
un-
17
An expanded and positive role for the urban
"joint
is being proposed through techniques such as
"multiple use of highway right-of-
development" and
other projects
opening
thus
corridor,
the highway
in
groups
aesthetic values
economic and
social,
up
incorporation
techniques envisage
Such
way."(9,10)
freeway
in
the area with
opportunities
adversely affected groups.
the
of
of
impacted
and coordination of
freeway
the
design,
for negotiations with
Such negotiations could form
the basis for incorporating the interests of adversely
impacted groups, by providing community services, revenues
from air-rights construction, and multiple use
of highway rights of ways.
Comparison of such broader framework of analysis
with the conventional practices indicates
and technical gaps as well as
give
should
us
insight
some
information
legal constraints, which
into the
dilemma of
the
For example, at present the highway
"highway engineer".
engineer is provided with a series of basic information
maps,
including topographic, geologic and soil maps with
property
The aerial photographs with the aid of
enables
has
churches and cemeteries,
and woods, streams and crossroads, marked on
marshes
them.
lines and values,
also
him to
a
few
see
the
terrain
in
'prediction models'
design alternates
to
the
stereoscope
three dimensions.
for relating
goal variables
of
He
generated
"legitimate"
18
and
"road user"
highways
cost of new
and
time
elements
features
tance,
relationships,
and
Then,
there
paring benefits
Benefits
reduction
highway
is
of
costs
and
the
various
The
facility.
costs
are
necessary to
for
com-
alternates.
and
construction
those
obtain
of
these
(17)
of a
construcsavings.
are
considered descriptively
conclusion of
the
benefit-cost analysis. (18)
there
are
federal
and state
prescribe the use of highway funds
uses'
research
factors
Finally,
way
knowledge
operating costs
in time,
consequent upon
accidents
Any qualitative
the
these
the
evaluation method
a formal
tion and maintenance
after
15)
and
12)
(11,
(16)
include savings
in
design
of on going
a result
as
continuously updated
traf-
facilities to
14,
(13,
in details,
are explored
in these areas.
new
highway
the standard
traffic engineering manuals
relationships
is
In
and human
and predicting
fic volume and capacity of the highway
them.
highway
dis-
sight
vehicle operatinq
and
response mechanism characteristics);
accomodate
geometric
predicting
curvature,
(through speed,
safety
of
predicting user's
characteristics);
and vehicle
and
(through estimation
(through speed,
cost
'predic-
few
construction
and services);
travel
the
include
His
agencies.
the highway
engineering quantities
travel
primarily
include predicting
tion models'
operating
groups
These
interest groups.
l9).
Until
recent past,
laws
which
for legitimate
'high-
right-of-
way acquisition procedures did not consider special
19
value,
inconvenience and possible hardships to the
owner, in the appraisal of property values and compensations).(20)
The entire hierarchy of state and
federal
General Accounting Office at
highway agencies with the
its apex, watches over the highway planner's
expenditure, to assure the compliance with
law.
Now, it may be argued that for consideration of a
wider range of goal variables and interest groups, we
need:
1)
An expanded situational data base, and
better prediction techniques to be able to predict
the consequences of highway design variables at the
individual
and community level.
Though we
ways had intuitive notions about the
we need better
sions,
have al-
consequences,
tools to produce wiser design deci-
as well as convince the participants in
decision making.
procedures are
In those areas where prediction
lacking
play a useful role.
situational data base
For example, to consider
'Community Disruption,'
maps could be prepared dis-
playing socio-economic variables
ownership, age,
could
such as home
income level, and ethnic groups.
Such display techniques would indicate not only
'how many' persons, but also
'who' is being af-
fected by the proposed route. (21,
'residential linkages' (23,
centers, such as
22)
Furthermore,
24) with other activity
schools, churches and local
20
shopping centers could be plotted to
the disruption of
mize
these
study and mini-
linkages by new
highway.
2)
A broader evaluation process:
reach a decision as to which of
highway alternatives is
In order to
several possible
most desirable,
the
full
spectrum of impacts of a highway must be weighed.
Furthermore, collapsing the
into
intangible values
one variable, and reduction of all the
effects of
transportation system to a single common denominator
(i.e. dollars) has the misleading advantage of
simplicity. (25)
Such practices are particularly in-
adequate where the costs
and benefits
do not have
(e.g., physical and mental
identifiable market price
pain, injury, or pleasure), (26) or have
different
values for different segments of population
time has different value
the blue
(e.g.,
for an executive than for
collar worker, (27)
and $1.55
(28)
an hour
can not be considered for everyone and everywhere).
These
considerations signify the need for
a
broader evaluation process, which should provide
basis
the
for bringing together the disparate desires of
the various actors, and clarifying issues
in an ef-
fort to produce agreement on an equitable
course of
action through negotiation and exploration of tradeoffs. (29)
21
However, it may be emphasized that even though the
prediction of consequences of alternate highway designs may be objective
(hopefullyl),
consequences may not be,
of these
be completely objective.
the evaluation
and perhaps cannot
Evaluation involves placing and
weighing utilities of impacted actors on the predicted
consequences of design alternates.
ties
But people's utili-
and values differ from place to place and
the "norms and privileged issues of time.
is
thus
change with
The effort
(30)
to increase the level of rationality in decision
making.
An institutional and legal framework conducive
3)
to such broader design and evaluation process.
and state
must be
Federal
laws have required that hiqhway trust funds
used on purely
"highway uses."
Obviously, the
highway planner had to conform to these laws for approval
of their plans.
broader
Highway use has been given successively
interpretations in recent years.
1962 Highway Act, requiring
The
comprehensive trans-
portation planning, the 1965 Highway Beautification
Act,
and the 1968 Legislation permitting the use of
highway
funds
to cover relocation expenses, are in-
dicative of gradual broadening of the definition of
highway use,
on
despite Bureau of Public Roads'
emphasis
(a) maintaining control of highway planning and
decision making by the States
(in response to state
highway departments pressure) and
(b) avoiding
22
additional delays in interstate highway construction
schedules. (31)
Furthermore, the passage of Federal legislation
for wider use of highway funds does not insure relief of
legal constraints at the State
are great variations
in State laws,
definition and scope of
There
level.
regarding the
'highway uses',
and speci-
fic state enabling legislation is required for
the highway agency to engage in multiple use of
highway right-of-way and joint development projects.
From the
foregoing discussion it is evident that
for a broader highway location design process, extensive
research is needed for the development of
prediction models and techniques,
search and policy changes
along with re-
in evaluation process and
legal-institutional framework.
This research is an
effort to respond to the need for such prediction
techniques
in the highway location design process.
It is realized, however, that prediction of
the
impacts of highway location alternatives
in an
urban area is a difficult problem, particularly the
social
impacts.
For many significant impacts, for-
mal prediction procedures are unavailable and we
will have to rely on
'experts judgment' until such
techniques are developed.
Alternatively, where
participation is being used, the individuals
23
directly affected may express
either themselves
their evaluations,
or through spokesmen. (32)
Following comments from NCHRP
port (33)
Study Design Re-
should give us further insight in develop-
ment and application of prediction techniques,
in
the highway location design process:
"Unlike prediction in the physical sciences,
prediction in a specific 'real world' location
problem cannot be completely deterministic.
The anticipations presented by a prediction
process in a social or politic setting must
at best always be considered as approximaThis is due first to the economic
tions.
infeasibility of obtaining anything close to
Secondly, one is unable
'perfect knowledge.'
to rely upon the various actor's use of consistent decision making criteria such as "pure
In a
rationality" or "pure self interest."
highway location process, predictive determination becomes all the more difficult due to
severely limited amount of control the
planner has over any but purely highway deNo matter how sophisticated the
cisions.
prediction technique may be technically, its
results must always be considered with caution
and with a reasonable tolerance for its
range of error."
After
this review of the need for prediction
techniques in the highway design process, the rest
of this study
is devoted to its specific objective,
which is prediction of noise effects of highways in
urban areas.
This would include
analyses of noise
level relationships with highway design variables on
one hand, and peoples reaction on the other, leading
to development of noise prediction and control
guides.
us more
Their application
to Case-study should give
insight into their practical value
and
24
expected effectiveness;
these issues
we shall
in the conclusions.
comment on
CHAPTER
Vehicle
Noise
Noise
by
the
Measurement
the
cardinal fact
lem
must
more
Noise
define
the
vehicle;
in
In
this
analyze
for predicting
Parameters:
Sound
(and consequently
The
ear
sound pressures,
meter
and
as
ear
a
as
the
Noise
pressure.
feelings,
values
emphasizes
a noise
prob-
and
assess-
its
and environment
values
These
shall
and
discuss
"People's Reaction
chapter,
first, we
related to
them
to
shall
freeway
noise)
to
which can be
a
motor
traffic noise.
is a
sensation pro-
fluctuations
very wide
scale
in
range
measured by a
a decibel
25
the
rationale behind selection
result of
responds
expressed on
and we
undesired
connected with physical measure-
particularly
and then
duced through
description
Chapter V,
terminologies
of a measure
their
complex indeed,
later
a Measure
is subjective;
rather human
From Freeways."
ment of noise,
A.
and
of
"sound which is
physical measurement.
are
detail
Selection
simple
that noise
a matter of
than of precise
in
This
involve people
environments
--
been defined as
has
recipient".(l)
ment is
III
(dB).
sound
air
of
level
2
The
1.
Decibel
--
What
is
it?(2,3)
Decibel, also called by its abbreviation,
"dB" is
frequently used in noise
studies, and
it represents a ratio of two 'quantities.
Since
air-borne sound is a variation in atmospheric
pressure, the pressure variations are used as
The reference pressure
the measure of the noise.
is usually taken as the threshold of hearing for
a person with very good hearing and has been set
0.0002 microbar.
at
noise
level scale.
is
This
"0"
decibel on the
Because of the great range of
sound pressure, it is convenient in measurement
and calculations to express the
on a logarithmic scale.
NdB
The number of decibels,
is given by the following
NdB =
20 log
ratios in units
formula:
Sound Pressure (in microbars)
0.0002
Because of the logarithmic definition of the
decibel it is not possible to add dB's directly.
We
shall discuss dB addition in more detail in
Chapter IV.
2.
Frequency Bands:
The noise we measure
is rarely pure tones.
It is usually a jumble of sounds that may range
from a low frequency roar to a high
squeal.
We react to these
frequency
sounds in different
27
ways that depend not only on the overall levels,
composition of noise as a
but also on the
function of frequency
In order to
(or pitch).
measure this composition, we make a frequency
analysis, which indicates how the sound energy
is distributed over the audible range of freIn this analysis, the
quencies.
energy is
electronically separated into various
frequency bands,
the audible range
bands, the center frequency of
63,
125,
The
for example octave bands.
octave bands cover
31.5,
acoustic
250, 500, 1000,
in ten
these bands are
2000, 4000,
8000
and 16000 Hz.*
The analysis yields a series of
for each band, called "band levels,"
octave bands,
"octave band
band in which a reading of
levels."
or,
for
Hence, the
level was obtained must
be specified if the information is
Fig. IV-l on page 37
levels, one
to be
of value.
illustrates a typical plot
of octave band spectrum of automobile and
truck noise
sources.
*Hz is abbreviation of hertz which means
cycles per second.
frequency in
3.
Weighting Networks: (5,6)
The apparent loudness
that we attribute to
sound varies not only with the sound pressure
but also with the
effect
is
taken
frequency of the
into account
This
sound.
to some extent by
"weighting" networks included in an instrument
designed to measure sound pressure level, and
then the instrument is called a sound
meter.
level
Contemporary sound level meters provide
three frequency weighting networks, labeled
"A",
"B",
and "C".
The
"A"
network provides the
most emphasis for higher frequencies and is supposed to have a frequency response roughly
comparable to the inverse of
response of the human ear.
provides somewhat less
the frequency
The
"B"
equalization.
network
The
"C"
network provides, in effect, a uniform unequalized response over most of the audible
frequency range.
The unit of measurement of
sound pressure level,
dB,
the decibel, abbreviated
is modified by a subscript when one of the
frequency weighting scales is
sound measured on the
level meter would be
dBA. (8)
"A"
employed.
Thus
network of a sound
reported in units of
a
B.
The
noise
"A"
Noise Measure:
Selection of a Vehicle
literature
review
indicates
that
"A"
scale
level in units of dBA as measured with the
weighting
network
of a
in measuring
practical
sound
meter
from today's
noise
applied to
vehicles. (9,10)
When
highway
this measure
vehicles
level
the
highway
noise
from
as
correlates
is most
well
with human judgment of the acceptability of the
noises
as do
been
selected as
this
study also.
which
led to
of
a measure
Following
selection
of
vehicle noise
for
is a discussion of the
measures of
various
criteria,
dBA has
elaborate methods.
the more
and rationale
noise,
dBA as
acceptable
an
measure:
1.
Criteria:
The most basic
measure
concern
selecting a
stimulus
noise
for the
in
is
that the
measure must discriminate between different
vehicle noises on a basis
similar to the disIn other
crimination evidenced by people.
words,
cise
a measure
no
from a physical point of
relevant for our
that Truck A
human
of noise,
is
observers
"noisier" than
use
if
Truck
B
indicate
not
than Truck
that Truck A
pre-
is not
view,
it does
"noisier"
agree
matter how
B when
is
as heard by them.
We
3Z0
need, then, a measure that correlates well with
subjective judgment of the noise and yet a
measure which is capable of
a good objective
These
definition and simple measurement.
criteria are summarized as follows:
a.
judgments
A high correlation between
of acceptability of
values assigned to
the noises, and
the noises by this
measurement unit, and
b.
A unit obtained as directly as possible
from field measurement rather than from
extended calculations.
2.
Various Measures of Noise:
The various measures in common use today
for description of noise
groups.
tend to fall into two
One group attempts to represent as
faithfully as possible the
judgments in
results of human
laboratory situation.
Such calcu-
lations effectively preclude direct measurement
in the field, due to complex procedure involved
in analysis of noise data taken in octave
bands of
The
that
frequency. (12)
second class of measures are
those
can be made directly at the measurement
site with simple
instrumentation
(i.e.,
a
sound level meter, with built in frequency
weighting
networks).
two groups
the
in
Measures
are described below: (13)
a.
Measures:
Psychologically Derived
Loudness
a.l.
pressure
level
an
average
as
loud.
with the
The
-
of
a
from the
of normal
This
to be
observers
sound
judged by
tone
cps
1000
the
of
The measure
sound derived
a
strength of
Level
equally
is a logarithmic quantity
'phon' being the unit of measure.
loudness level of a sound is calculated
in specified
from sound pressure levels
frequency bands.
Two systems are commonly
employed for such calculations, one due to
Stevens
(14)
(LL ),
bands, and one due to Zwicker
contours
these
systems
based on
(15)
use
equal
'
L
bands.
frequency
using one-third octave
Both of
frequency
using octave
loudness
frequency band analy-
.(16)
a.2.
Loudness -
The measure of
a linear basis, giving
mately proportional
to
loudness, on
scale numbers approxiThe
loudness.
unit
of measure is sone. (17)
As a reference, a
sound pressure level of
40 db
relative to 0.0002 microbar
cycle
tone
is
sounds twice
taken as
(40 phons)
for a 1000-
1 sone.
A
as loud is two sones.
tone
that
32
a.3.
Perceived
which purports
to
rather than the
computational
to
rate
The
the
with equal
A
measure
noisiness,
The
loudness of a sound.
scheme,
computation
loudness
-
Level
due
co-workers yield
and his
PNdB.
Noise
level
to
Kryter, (18)
in
a measure
approach is
calculations
of
similar
Stevens,
"noisiness" rather than "loud-
ness" functions
PNdB should be
employed.
considered as the more precise measure in
laboratory
and where
studies
new noises
are
different frequency characteristics
It is widely employed in noise
encountered.
measurements
from the
a.4.
Interference
Speech
measure of
noise which
relationship
The
SIL
is
of
to
aircrafts.
Level
bears
arithmetic average of
A
a.direct
the masking of
reported in
(SIL) -
speech. (19)
decibels and
is
the
the sound pressure
levels in the octave frequency bands of
600-1200 cps,
1200-2400 cps,
and the
2400-4800 cps.
b.
Physical
b.l.
Measures
Overall
of Sound:
Sound
Pressure Level
(OASPL) -
The pressure level measured by a uniform
frequency response
system.
It
is
a measure
2~'
of
root-mean-square
decibels with
a reference
as dBC,
when read on
sound
level meter.
b.2.
A-Scale
Sound
of sound pressure
base
of
It is also referred
2 x 10~4 microbars.
to
in
sound pressure
the C
Level
scale
(dBA)
-
of
the
a
value
in decibels measured
level
by a sound level meter which has the
fre-
quency weighting network designated by
'A'.
This
is an equalization circuit which
is supposed to have approximately
the in-
verse frequency response characteristics of
the human ear at 40-phon loudness level.
A number of analyses of the usefulness
of dBA has been made.
shown excellent
Some of these have
agreement
between
the
and subjective effects, while others
relatively wide discrepancies.
show the wide discrepancies
dBA
show
Those that
usually include
comparisons of high-level narrow-band noise
or pure tones with broad-band noises.
The
most consistent
the
results
are
found when
noises that are being compared are
in character,
of
as,
for example, in ratings
the objectionableness
large
number
of
similar
of
noises
automobiles.(20)
from a
Hence
it
34
has been widely
noise
motor vehicle
studies. (21)
BBN has
tical
used in
performed
analysis, with
an
extensive
sets of noise
statissource
descriptions
and judgments
from panels
observers to
determine the
degree
between each of
relation
measures,
discussed above,
judgments. (22)
lized
of
the data
For this
from two
character;
and
analysis BBN
experiments,
of
utiboth
in
Industries
Research Founda-
the National
Physical Labora-
and Motor
of
results
cated that
are not
Sound Pressure
Interference
Speech
accurate predictions
motor vehicle noise.
difficult to
measures as
basis
However, dBA
being
of
good
any one of
better
these
is the
(SIL)
of reaction
judgment, and
select
Level
Level
to
On the other hand all
the other measures exhibited
tion with human
indi-
this analysis
of
both Overall
(OASPL) and
the
sets
England. (23)
The
on
the
Asmour Research Foundation
tion Studies
tory.
cor-
alternate
comprehensive
them sufficiently
Studies
the
of
of
it would be
those
than the
others
experiments
alone.
only
high correlation with
correla-
measure
subjective
havinq
reaction
that can also be read directly on a commercially available meter having
Considering all
standardized performance.
other factors,
be
BBN
has proposed that dBA
selected as the basic measure
present day motor vehicle noise.
"A"
scale noise
level
for the
Also, the
is being adopted as
an international standard for measurement
of vehicle noise. (24)
Furthermore, the
availability of high-
way design variables and noise relationships
and acceptable noise
levels for various uses
in terms of dBA, proved to be of great
value for case
this study.
application, envisaged in
Hence dBA is
selected as a
measure of freeway traffic noise, in
this
study.
This completes our
discussion of noise
parameters and selection of
measure.
a suitable
The next chapter is devoted to the
prediction of noise from highway design
variables.
CHAPTER
A.
SOURCES OF
The
TRAFFIC
NOISE
major vehicle
noise
traffic
categories
of muffling and
standards
in
the
description
sources even
noisy
operations
are
of
The
cars.
trucks and passenger
large
are
inherently very
are
trucks
Highway Design Variables
of Noise From
Prediction
IV
though
generally
The cars represent a large portion of the total
good.
traffic, and do not differ greatly as noise sources, in
Motor
from trucks.
in noise
contrast to variations
are an occasional source of noise and their
cycles
noise performance could be easily
vehicles
the
in motion:
tire roadway interaction
stances,
intake
constitutes
noise
at
a significant
from cooling fans,
of
sources
are two major
There
improved. (1)
from motor
exhaust system
engine
Under some
system.
the
noise
and
the
circum-
carburetor opening
noise
source,
and
the noise
valve lifters, superchargers, gear
boxes, and many other parts is often detectable.
Most
modern passenger cars employ good mufflers as factory
equipment.
cycles,
the
pipe
hot rods,
sports cars, motor
and intermediate size trucks, on the other
often have
hand,
is
Used cars,
inadequate mufflers.
truck or motor cycle
and either no muffler,
36
with a
or
a
The
case
extreme
straight exhaust
rodded muffler.
Due
90
C14
C
0
C)
80
_
_
__
_
_
70
0 60 mi/hr Autos,
2 Vehicles/sec,
100 ft from Freeway Centerline
a)
Range of Maximum Levels from
60/
Individual Trucks with Typica
from
Exhaust Muffling, 100 ft
Trucks
Cj):i 50__
_
_
U)
Q)
ra
s 401
o
31.5
dBA
63
125
250
500
1000
2000
4000
Octave Band Center Frequency in Hertz
FIGURE
IV-l.
TYPICAL FREE-FLOWING AUTOMOTIVE TRAFFIC NOISE
Sources and Observation Point on Grade
No Shielding
BBN (12))
(Source:
SPECTRA
8000
to these factors
the general noise
levels predicted
may be exceeded occasionally by as much as 10 to 15
Fig. IV-1 shows the typical octave band spectrum
dBA.
shapes
freely flowing automobile
associated with the
and truck noise sources.
B.
VARIABLES IN VEHICLE NOISE GENERATION
The major variables in highway traffic noise generation are
volume and composition of traffic,
the vehicles, the kind of road surface,
and the
(generation
including the effects of acceleration
of more power
load
The load may be interpreted
on the vehicle engine.
as
speed of
from the engine than is necessary to
maintain steady travel at the current road speed) ,
of up and down grade.
and
Acoustic barriers such as walls
and intervening structures,
and roadway elevation con-
figuration such as elevated, at grade, and depressed
sections further modify the noise levels,
distances from the highway.
has also slight effects.
into a
list as
Atmospheric attenuation
The variables
follows:
Speed
Volume
Distance
Percent Trucks
Acceleration
Percent of up grade
Roadway Surface
Atmospheric attenuation
at various
are summarized
Acoustic Barriers
Number of
We
shall
ables
and Elevation
lanes
discuss
and also
in some
detail
investigate
the
each
one
of these
vari-
effect of intervening
structures, and noise reduction characteristics of
walls and buffers that could be
incorporated in the
freeway design.
C.
THE ESTIMATION
OF
1.
Speed and Volume:
Effects
of
TRAFFIC NOISE
LEVELS
As mentioned previously, the noise of
a
freely-flowing automobile is dependent primarily
upon the traffic flow and average speed.
The
average A-Scale sound pressure level at 100
feet
from the center of freely-flowing automobile
traffic on grade is given by the expression
dBA =
37
+
10
log 1 0
m
+
20
log 1 0 V
where
m
= the
V
=
flow of automobiles/sec and
the average automobile
speed in
miles/hour (2)
The distribution of levels about this mean value
is dependent upon the particular traffic flow and
speed conditions.
A typical value of standard
deviation is ±3 decibels.
the
mean
noise
and Newman
levels
Inc. (3)
Table
IV-1 summarizes
developed by
These noise
Bolt Beranek
levels,
in dBA,
40
ft.
refer to a reference distance of 100
The columns of
side of the nearest traffic lane.
noise
hour
50, and 60 mph
levels cover the speed of 40,
for traffic
to the
counts from 500 to 40,000 vehicles per
for mixed traffic made up of about 95%
mobiles and 5%
trucks.
auto-
For different traffic
composition, roadway surface conditions and
ac-
celeration, corrections to these values will be
applied as discussed later.
Since the speed and volume ranges shown in
Table IV-1 covers most of the conditions
in urban
freeway design, it is adopted in this study as the
basis
for noise level prediction.
the case study,
However, during
noise level estimations for 25 mph
and 30 mph speed conditions were needed.
were
These
interpolated with the help of guides provided
by Bolt Beranek and Newman Inc.
2.
Effect of Distance:
For any single noise source,
the noise level
drops off at a rate of 6 dB for each doubling of
the distance from the source.
For a long line
of uniformly distributed noise sources, the
noise level drops off at a rate of 3 dB for each
doubling of the distance
perpendicular bisector of
(as measured
the line).
from the
Because a
line of traffic is made up of a somewhat nonuniform distribution of point sources, the drop-
41
TABLE
IV-1
APPROXIMATE MEAN NOISE LEVEL (IN dBA)
100 FT TO THE SIDE OF A STRAIGHT, LEVEL
ROADWAY AS A FUNCTION OF SPEED AND
QUANTITY OF TRAFFIC FOR MIXED TRAFFIC
OF 95% AUTOS and 5% TRUCKS.
TRAFFIC
COUNT IN
THOUSAND
VEHICLES
PER HOUR
AVERAGE TRAFFIC
SPEED
40 MPH
50 MPH
60 MPH
0.5
60 dBA
62
64 dBA
0.6
61
63
65
0.8
62
64
66
1.0
63
65
67
1.2
64
66
68
1.6
65
67
69
2.0
66
68
70
3.0
67
69
71
4.0
68
70
72
5.0
69
71
73
7
70
72
74
10
71
73
75
15
72
74
76
20
73
75
77
30
74
76
78
40
75
77
79
dBA
42
off of noise
pected to
levels with distance would be
fall somewhere between
rate of 4 dB seems to occur.(5)
Table IV-2 gives
3 and 6 dB per
Measurements
doubling of distance.
ex-
show that a
Thus,
the average noise level re-
deduction for distances beyond the reference
distance of 100 ft. (6)
for
The Table IV-2 values
any particular distance should be subtracted from
the Table IV-1 mean noise
levels in order to ob-
tain the mean levels at the required distance.
For distances beyond about 2000 to
3.
an
to actual energy
additional loss occurs,
due
absorption in the air.
This is
Table
3000 ft.,
reflected by the
IV-2 values for the larger distances
Effect of Truck Volume:
Large diesel trucks represent a relatively
small portion of total traffic on urban highways,
often 5% or less.
They are, however, impressive
sources of noise and are usually clearly audible
in the mixture with automobiles
in traffic.
The
noise from diesel trucks must be considered seriously because
they are
than passenger cars,
inherently much noisier
being of the order of 15
higher in noise level.
dBA
Other types of vehicles
such as motor cycles are noisy
largely because the
standard of muffling of their exhaust noise is not
TABLE
NOISE
IV-2
LEVEL CORRECTIONS
GREATER THAN
DISTANCE
TO ROADWAY
(FT)
FOR DISTANCES
100 FT TO ROADWAY
NOISE LEVEL
REDUCTION
(dBA)
100
0
200
4
300
6
400
8
500
9
600
10
800
12
1000
14
1500
16
2000
18
2500
19
3000
20
3500
21
4000
22
5000
24
6000
25
7000
27
8000
28
9000
30
10000
32
44
comparable to those
for passenger cars.
For
diesel trucks the standards of muffling and
mechanical conditions have been reported high,
by Bolt Beranek and Newman Inc.,
studies;
the
trucks are noisier simply because they radiate
relatively large amounts of acoustic power.
Correction to the 100%
various percentages
suggested as
car traffic, due to
of truck traffic have been
shown in Table IV-3. (8)
Table
IV-3
Truck Volume Corrections:
% of Trucks
in Traffic
Additional dBA
Corrections (dBA) to Values
in Table IV-1 (5% Trucks)
0
0
-2
2 1/2
1
-l
5
2
0
10
4
+2
20
8
+6
Column 3 of the above
derived for
tions.
4.
corrections
95% automobiles and 5% truck composi-
These will be
Table IV-1,
table shows the
applied to the values in
in our calculations.
Effects of Acceleration,
% Grade, and Intersection
Conditions:
It is obvious that acceleration,
and stop and go
up-grade,
(intersection) conditions put
45
extra power demand on car and truck engines, and
results in extra reaction between tire
way surface.
and road-
These conditions lead to higher
has suggested following dBA additions,
these conditions,
BBN
levels.
than normal cruise condition noise
due to
to the normal cruise values
However, one
recorded in Table IV-l.
has to
conditions carefully and
analyze the prevailing
exercise judgment in deciding as to which one of
these
conditions apply.
Maximum acceleration conditions
mobiles produce noise levels of
dBA above those for cruise
There is
the order of 6
conditions.
an effect of roadway grades on the
noise produced by trucks, but the
of trucks on 3 to
trucks
difference is
2 dBA between the average for samples
only about
roadway.
for auto-
5 percent upgrade and on level
On the other hand the acceleration of
from low speed on level roadways produce
noise levels that are
about 5 dBA higher than
those generated under cruise conditions.
These observations are summarized in Table
below.
Table
These
IV-l.
values have
to be
IV-4
added to dBA in
46
Table
IV-4 (10)
Corrections for Upgrade and Acceleration
uphill grade add 2 dBA.
1.
For 3% -
2.
For maximum acceleration
way
4%
(i.e. traffic entering road-
from an uphill approach ramp),
add 5 dBA to 50 mph
values.
5.
of Roadway
Effect
Surface:
No appreciable relationship between road surface and noise
from trucks has been observed,
except for certain tread designs.
that
will
such a relationship
It is probable
not be
strongly
evident for trucks because of the predominant
engine
and exhaust
passenger car noise
sources of noise, whereas
the
includes a greater component
of tire-roadway interaction noise.
degree of roadway surface
Hence the
roughness is found to
be an important factor in passenger car noise.
For further refinement in the estimation procedure
considerations should be given to the nature of
road surface, adding or subtracting
very
6.
rough or very smooth
5 decibels for
surfaces, respectively. (11)
Effects of Weather and Atmospherics:
Precipitation, wind, temperature,
and relative
humidity are possible atmospheric factors in sound
transmission.
Several
field measurements
show
47
that the average atmospheric
attenuation values
have a small effect on the dBA levels up to
2000 feet from the noise source.
less than 1 decibel at 1000 ft.
mately 2 decibels at
have been observed.
2000 ft.
(12)
Reductions of
and approxi-
from the source
However the
significant
end result is that practically none of the
factors offer any useful amount of noise
duction for long time periods.
atmospheric effects
These
In summary, the
seldom increase, but sometimes
decrease sound levels at
source.
re-
large distances
from a
decreases are usually of an
intermittent, short-term duration and they are
usually beneficial to the receiver when they
occur
(by giving slight temporary noise reduc-
tions),
but it is best not to
rely on them for
long-time benefits in terms of noise
control
design. (13)
7.
Effects of Acoustic Barriers and Elevation:
Walls, buildings,
rigid barriers,
embankments and other
large
if interposed to project well
beyond the visual line-of-sight between a noise
source and the listener will result in appreciable attenuation.(14)
This attenuation is in
addition to that produced by distance,
and is due
primarily to the acoustic shielding effect of
418
such structures.
Acoustic
shielding is provided
also due to changes in the elevation, by depressing or
elevating the roadway section.
The
acoustic shieldings could be achieved through a
combination of existing features of the site,
roadway elevation,and new barriers incorporated
in the highway design.
A designer should care-
fully investigate the opportunities to incorporate
an optimal mix of acoustic barriers in his design.
As we shall
see in the following discussion,
acoustic barriers provide substantial noise reduction and probably at a higher level than most
of the other feasible measures discussed so far.
However, feasibility of barrier also needs a
sensitive analysis of its conflicts with other
goal variables, e.g.,
conflict with driver's
view from the road.
Now we shall investigate and discuss the
various kinds of barrier and geometric configurations and their noise reduction characteristics.
7.1.
Effects of Walls:
The key variables
in-
fluencing barrier attenuation as described
by Rettinger are
shown in Fig. IV-2.(
15
)
Various authors have investigated the
relationships between these variable,
have proposed formulae,(16) charts,(17
and nomographs
(18)
to determine their
and
49
d.
WALL
O85ERVER
SouND SOUKCE
FIG. IV - 2 : KEY VARIABLES INFLUENCING BARRIER
ATTENUATION OF SOUND. (Source: Rettinger(15)
0
5
z
0-
0
100
FftEQ0racy 'CyCLESPE
1o00
SECOP4D
FIG. IV - 3 : SOUND ATTENUATION AS FUNCTION OF
FREQUENCY AND BARRIER HEIGHT , FOR THE CASE
SHOWN.
(Source: Rettinger(19) )
)
50
effects of noise attenuation.
Sound attenuation by frequency as a
function of barrier height for
and receiver distances
fixed source
from the barrier, as
calculated by Rettinger, is shown in
Fig.
IV-3
(19)
.
It has
been shown that sound
attenuation increases with increase in barrier height and/or a decrease in distance
between the sound source and barrier.
Weiner has reported that a practical
limit
(due to transmission through the barrier or
by-passing around it)
of the noise
reduction
due to shielding is somewhere near
25 dB. (20)
Fig.
Furthermore,
as shown
in
IV-3, the higher frequencies show
greater attenuation than lower
frequencies.
This greater attenuatuion of high frequency
sound is significant
for control of commu-
nity noise problems,
since such sounds are
judged more annoying than the lower frequency. (21)
However, the presence of a
barrier for long
vide
stretches of road would pro-
rather a dreary view to the
driver.
Hence, barrier of limited height, e.g.
3 1/2
ft.,
permitting visibility of the
surrounding area have been suggested. (22)
Note:
Each of these four distinct
constructions give the same
noise reduction (at 500 cps,
22.5 dB bElow the case at
right).
S.L 100d
_L60))))
SO
24"
8
o
/oo.
-L
774
-
d
(
..I
St
FIGURE IV-4:
=77.,
d1,,
SOUND ATTENUATION BY DIFFERENT DEPRESSED ROADWAY
CONFIGURATIONS EQUAL TO THE SIDE WALL
(Source:
Rettinger
(23))
(
52
Depressed roadways
reduction
equal
Fig. IV-4
of depressed
attenuation equal
way.(23)
provide
a
to that obtained
bordered by walls.
examples
can
to a
level
by roadways
shows various
freeway,
wall
sound
producing
along
the
free-
The sound level reduction is
22.5 dB at 500 CPS in all cases.
the depth of
cut
must be
greater
As
shown
than
that
of barrier height to cause same attenuation.
The side slope
angle also affects noise re-
duction level of depressed roadway.
If
reflection is provided by the opposite wall,
attenuation will be reduced, because such
reflection tends
to reduce
the effective
height of the noise shadow.
is shown in Fig.
IV-5-a.(24)
This
condition
Sloping walls
of the cut can direct these reflected sounds
upward to prevent their penetration in the
acoustic shadow.
But sloping also reduces
the effective barrier height for the sound
coming directly from the source.
dition is
illustrated in Fig.
This con-
IV-5-b.
Other
solutions involve the erection of a partial
roof or overhang on the walls of the cut or
use of dense planting on embankment to
scatter and absorb reflected sounds.
$0Oj140
CUT WITH
VERTICA WALLS
(1)
CUT WITH
SLOPED WALLS
FIG. IV-5
SOUND ATTENUATION EFFECTS OF
REFLECTING AND SLOPING SIDE WALLS
(Source:
Cohen(24)
)
7.2.
Effect
of Woods:
hedges
have
frequently
measure of noise
out
to be
density
Fences
practicable.
to
living
This
seldom
Not only
is
and
a
turns
great
required with branches
the ground but also
height of planting
trees
been suggested as
control.
of planting
reaching
of
an appreciable
is necessary. (25)A
dense growth of woods with an average tree
height of at least
30 to 40
feet above the
line-of-sight from the roadway to the point
of interest will produce about 2 dBA per
100 feet depth of woods.
Scattered trees
offer no noise reduction.
A visual screen
of trees that hides a busy roadway has a
psychological value even though possibly of
little
acoustic value.
Noise
reduction due
to woods,
solid walls,
and various cases of depressed roadways are
summarized in Table IV-5. (26)
7.3.
Effects of Elevated or Depressed Highways:
We have already discussed the effects of
locating a roadway
in
a cut
section,
and ob-
served that noise reduction is achieved due
to shielding effect.
Such acoustic shielding
has been observed for elevated roadways also.
Field measurement data
elevation
conditions
from a
for various
BBN study
are
TABLE-IV-5
NOISE LEVEL REDUCTION DUE TO VARIOUS
ATTENUATING STRUCTURES BETWEEN
ROADWAY AND POINT OF INTEREST
1.
DENSE WOODS
(Approximately 30-40 ft. minimum average
height above line-of-sight from roadway
to point of interest; average visibility
penetration through the woods not over
about 70-100 ft.
Note:
"visibility penetration:" cannot see 1 sq. yd. white sheet
beyond about 70-100 ft.)
2.
SPARSE
3.
SCATTERED TREES
4.
3 FT
WOODS
HIGH
2 dBA per
100
ft.of woods
1 dBA per
100
ft.
0 dBA
(no reduction!)
SOLID BARRIER WALL ALONG
4 dBA out to
2 dBA beyond
5.
EFFECT OF SLOPED CUT
OF ROADWAY
(300
-60*
HEIGHT OF
EARTH ABOVE
ROAD SURFACE
5 ft
10
15
20
25
30 or higher
OF
ROADWAY
from roadway
Horizontal) ALONG
EDGE
NOISE REDUCTION
BEYOND
OUT TO
500 FT
4
6
8
10
13
16
higher
EFFECT OF VERTICAL CUT
EDGE OF ROADWAY
ft.
ft.
from
5 ft
10
15
6.
EDGE
500
500
HEIGHT OF
EARTH ABOVE
ROAD SURFACE
20
25
30 or
of woods
(750
-90*
500 FT
2
4
6
8
10
12
from Horizontal)
NOISE REDUCTION
OUT TO
BEYOND
500 FT
500 FT
5
7
10
13
16
18
3
5
8
10
12
14
ALONG
TABLE
NOTES:
1.
IV-5 (continued).
Noise reduction values in Steps 4, 5 and 6
assume there is no higher vertical barrier
on the opposite side of the roadway that
could reflect sound into the "shadow zone"
provided by the wall or cut used to achieve
noise reduction.
If a higher vertical
barrier exists on opposite side, reduce the
effectiveness of the acoustic wall or cut
by 3 dB
for each 10 ft. excess height of the
opposite wall above the acoustic wall, but
only up to the point where the effectiveness
of the acoustic wall is reduced to 0 dBA.
2.
The noise reduction values of Steps 5 and 6
may be considered to apply if the surface of the
cut is within 300 ft, of the edge of the roadway.
For distances beyond 300 ft., use only one-half
the amount of noise reduction given by the
appropriate column of values.
3.
For an acoustic barrier to be completely
effective, it should project beyond the line
of sight for traffic noise sources in all
lanes (by the heights indicated in Steps 4,
5 and 6),
and it should be assumed that the
noise source of a truck is located at the
upper end of the exhaust stack, usually about
8 to 10 ft. above road level.
'ii
I
I
t
50
I
100
? OO
400
8oo
shown in Fig.
These measurements
IV-6.
were made adjacent to various 6 or 8 lane
divided freeways, where
12
lane widths were
feet, and change of elevation was
typically 20 feet.
The difference
in dBA between the at-
grade and other configurations
indicates the
noise reduction obtained from shielding.
For
example, at a distance of several hundred
feet or more from the highway the noise levels
are 7 dB lower
from depressed conditions
For lo-
than that from a highway at-grade.
cations within several hundred feet of an
elevated highway, the noise
much as 5 to
dition.
10 dB
lower than at-grade con-
However, beyond 400 ft.,
vated highway produces the
as
7.4.
levels may be as
the ele-
same noise levels
if it were on-grade.
Effect of
Intervening Buildings:
The
litera-
ture survey has provided information on prediction of traffic noise
along the highway, having
the noise source.
systematic
at various points
line-of-sight to
But there is very little
information available for
common case where the
the
area is shielded from
the traffic noise by one or more intermediate
buildings.
The
following two studies provide
59
us with some insight into this area.
A study undertaken in Boston to investigate the effectiveness of an outdoor communication system
attempted also
sound propagation across
into side
sections,and
sults of this
to
streets
record
and interThe
streets.(28)
study showed noise
re-
level re-
ductions between 9 dB at 160 Hz and 15 dB
at 5000 Hz, for sound propagation out of
line-of-sight into a side
this was
was
a very
street.
limited study;
However,
noise
source
fixed, and only one intersection con-
figuration was
studied.
In the
of
the study
course
their
investigations
for
"Noise in Urban and Suburban
Areas,"(29)
BBN
also conducted a brief series
of measurements to explore the situation in
which the point of
interest did not have
line-of-sight to the traffic due to intervening buildings.
This noise penetration
study was made around the Ventura Freeway,
in Los Angeles,
California.
ments were made along three
Sound measurelines perpen-
dicular to the Freeway and extending into
the residential areas approximately
Except
for the nearest
set,
2000 ft.
all measurement
positions were blocked visually from the
C0
at
least one
row of
results
indicated
a noise
Freeway by
Their
buildings.
level re-
duction of-1-0-20 decibels from the
and
unshielded case,
remained essentially
of
reduction
constant, independent
intervening
number of
the
also that the
structures.
In
first shielding structure
other words, the
was most effective in introducing a noise
reduction, and subsequent structures did not
significantly.
reduce the level
Following comments and guesses are made
to further clarify our understanding of the
role of
noise
intervening
structures
in
traffic
reductions:
a).
Although the row of buildings do
form a kind of barrier between the expressway
traffic
and surrounding community, this bar-
rier is not a solid barrier due to the open
spaces between the
Since noise
successive buildings.
from roadway traffic
tinuous column,
buildings will
forms a con-
the open slots between the
be penetrated.
This penetra-
tion will be probably along the streets perpendicular to the noise column of freeway.
And the side of houses
will be
along these streets
subjected to higher levels of noise,
even though the
front portion of houses may
have some acoustic
shielding due
vening structures.
to inter-
Although the BBN study
along the Ventura Freeway (30)
does
indicate
noise reduction for the points not having
line-of-sight to freeway traffic,
it did not
record simultaneously noise levels
for those
adjacent point, having a line-of-sight to
the freeway traffic.
It is highly probable
that at such points the noise
much higher.
buildings
acoustic
level could be
Space between the successive
could be
shielding
a
or
factor
into providing
exposure at
various
locations.
b).
Topography of the site
in relation
to freeway could destroy or augment the
shielding effect of intervening structures.
Those houses
located at a steep side-hill will
have a line-of-sight to freeway traffic, despite the presence of a row of houses between
them and the freeway.
And for those houses
located on the opposite side of a hill, the
topography could further augment the
shielding.
Fig.
IV-7
Sketches
(a) and
(b)
acoustic
in
illustrate these conditions
respectively.
c).
A combination of site topography
and structures
configuration may result in
62
o5
the partial exposure to the
noise.
freeway traffic
If only a part of the total line is
exposed, and all the rest of the line is
completely removed acoustically, as visualized
IV-6, (31)
by the sketch accompanying Table
then a reduced amount of noise would be
radiated by the roadway.
The amount of noise
reduction, as a function of exposure angle,
is
given by Table
center of
IV-6, when the
the exposure angle is approximately perpendicular to the roadway.
recommended by BBN,
These values are
and are
to be subtracted
from the values of Table IV-l.
For a more complex exposure condition at
point of interest, a complete acoustical
required, and is
analysis will be
d).
The
recommended.
immediate rows of buildings
along
a highway, though may provide acoustic
shielding for the areas behind them, are
themselves subjected to the
of traffic noise.
full severity
The residents of these
buildings will have to bear the
traffic noise.
be
full brunt of
The highway designer has to
sensitive to noise impacts on immediate
rows of houses.
e).
The dense traffic movement on high
speed expressways
in urban areas may
cause
64
TABLE
IV-6
NOISE LEVEL CORRECTIONS FOR EXPOSURE TO
PARTIAL SECTION OF ROADWAY, APPROXIMATELY
CENTERED WITH RESPECT TO POINT OF OBSERVATION
EXPOSURE ANGLE
(degrees)
NOISE LEVEL REDUCTION
(dBA)
180
0
120
2
90
3
70
4
50
6
35
9
15
12
HiDDEN" _EXPOSED ROADWAY
EXPO5URE
ROADWAY
ANGLE
0
MIDDENO
ROADWAI
sound transmission into the building areas
via connecting structures,
the airborne noise.
in addition to
And although the airborne
noise is attenuated due to building walls,
sound transmission through connecting
struc-
tures could create significant problems for
the occupants.
Limited data have
indicated
that structure borne noise levels in
buildings, located beside or over medium
speed
(25 to
40 mph) highways,
fall in the
range of 60 to 80 dB in the 20-to-75
cps
octave band and drop off with frequency at the
rate of 10 dB per octave. (32)
ing general suggestions for
transmission of
Also,
follow-
suppressing sound
this nature have been made by
the author of the above mentioned study:
i)
Provide smooth,
fine grained road
finish.
ii)
Have no expansion joints
in the road-
way near critical buildings.
iii)
Have no drainage grills running across
the roadways.
iv)
Provide suitable vibration--isolation
joints between the road-bed and the
structural members
of the adjoining
buildings.
In the foregoing discussion attempts were
made to investigate the shielding
effects of
66
in roadway
due
elevation
to their
tenuating
changes
detail,
more
in noise
figures
tables and
sense.
and
and
presented
employed exercising judgment
here should be
and common
in somewhat
relative importance
The
reduction.
adequate
structures
intervening
barriers,
systematic
effects of
felt that
it is
However,
data
for
the
at-
intervening buildings
are not available at present and this area
requires further research.
8.
Effect of
Lanes:
The noise levels discussed in this
chapter
all refer to traffic on a single lane or a
single lane equivalent roadway.
This single-lane
equivalent can be considered as a hypothetical
carrying out the total flow
of real vehicles).
lane
(ignoring the overlap
On the basis of their field
and simulation studies, BBN recommends that it
should be considered as located at a position
displaced from the closest lane to the observer by
a distance equal to the
of
square root of the number
lanes times the lane width.
a four-lane highway the
would be at the
to the observer.
employed. (33)
For example on
effective pseudo-lane
location of the second
The
lane closest
following table may be
67
Table
IV-7
Pseudo-Lane Location
Number
Lanes
Displacement Away
From Nearest Lane
in Lane Widths
of
2
3
4
5
1.4
1.7
2
2.2
6
2.5
7
8
2.7
2.8
For dividend highways having significantly wide
median strips, noise
levels on the two sides should
be treated separately,
then the sum is obtained
logrithmically, as below.
As an alternate
to the single-lane-equivalent
lanes having quite different traffic characteristics can be
estimated separately and the dBA values
combined according to the
following table. (34)
This method of decibel addition is in conformity
with the recommendations of Handbook of Noise
Measurement.(35)
Table IV-8
Addition of Decibels
If higher level
exceeds lower by
10 dBA
5 to
2 to
0 or
9
4
1
The
sum exceeds
higher level
0 dBA
1
2
3
by
the
Tnus,
for two
values
at
lanes
72
further
This might be
would combine to 76 dBA.
74 dBA
dBA and
combined with a third lane at 76 dBA for a three
lane
In
the
real world
In
the picture.
A
noise
levels
many other considerations
fact,
but
patterns will
and access
a proposed noise
obstruct the
raised roadway may provide
"view
wall may
from the
shielding
noise
enter
reduction may
For example, a solid
conflict with other goals.
reduce
dBA.
situations,
cost, aesthetic,
such as
into
79
estimate of
in
the
road".
im-
mediate environment, but may be aesthetically undesirable
road.
by providing an ugly view of the
The noise reducing
measures, and relalationships of highway design variables
to
noise
levels
discussed
in this
chapter will
have
to be
considered in the framework of a broader trade-off analysis.
With the knowledge of these
relationships a highway en-
gineer can become aware of the noise impacts of his design,
and can include
these impacts in his
trade-off analyses.
In fact at the time this study was in progress, there was
a major controversy over the noise impacts of elevated,
grade,
and depressed design
Expressway, passing
alternates of Elysian
through the
Old
at-
Fields
French Quarters
of
New Orleans.
The
levels,
relationship of highway design variables to noise
discussed in this chapter, are synthesized into
systematic design
guides in
chapter VI.
CHAPTER V
Noise Pollution -People's Reaction
To Noise From Freeways
A.
NATURE
OF
THE
PROBLEM AND
IMPLICATIONS:
Establishing objective measures of people's discomfort
and reaction to
noise,
is
much more
complex
than prediction of noise levels from freeway traffic.
Variables such as difference in psychological make up,
the
socio-economic
the message
class,
carried by
noise,
characteristics of noise,
background noise
one
the way
the
the
noise
is presented,
pressure,
nature and
(ambient noise),
the
(or night),
add up in forming people's perception of
Under the
general
mentioned that noise
many ways,
as
may have
an
of
noise,
influence
it has
on
been
health in
and recreation;
may disturb concentration, and perhaps
task;
"noise pollu-
it may interfere with specific activities
communication, education
ficiency of
all
for example by preventing sleep, or indu-
cing stress;
such
effects
extent of
type of activity
is engaged in, and time of the day
tion."
frequency,
it
affect the ef-
someone working at a difficult or skillful
it may affect personal
safety.
At different
times it may produce anything from exhilaration to
acute
is
irritation
defined as
in the
same
individual.
Since
health
"a state of complete physical, mental and
69
70
and
social well-being
there
and infirmity,"
for
tablished.
various
effects
Interference levels
automotive
(SIL) .
traffic
in terms
are made
is
(2)
the
thing
One
for
report in
New York,
of Speech
is
major source
Boston and Los Angeles
certain,
noise
of
in
Both Wilson
and BBN
Great Britain (3),
prob-
the
analyzes
urban areas to which people complain.
Committee
es-
been
have
from noise
a recent BBN report
and recommendations
that
affects
noise
that
doubt
In the area of effect of traffic noise on
communication,
lem,
no
However, no clear cut relationship and
health.
measure
is
of disease
absence
not merely an
(4)
show
study
that
traffic noise is generally the major source of bother,
locations, such as areas close to
excluding special
airports.
by
Another traffic noise survey also conducted
BBN concludes
that prediction
traffic noise is not as
intrusions
people's
reaction
straightforward as prediction
(for instance, that from aircraft fly-
overs) ,
BBN have
between
noise
highway
appears to
found moderately
level and
be
reaction.
so pervasive
direct relationships
However,
a part of
the
urban
the
neighborhood environment that people do not consider
its noise
apart from other aspects of
the environment.
Further, because urban highway is so important in
people's lives,
noise
is
to
In studies of other kinds of
of the noise levels. (5)
noise
of
judgment of annoyance with traffic
confounded with attitudes towards highways in
71
general, and
part of the
especially toward any highway that is
In view of this
immediate environment.
to
circumstance, in that survey attempts were made
place noise
in perspective
living near freeways,
to the
total picture of
including the advantages
as disadvantages, other than noise.
as well
Statistical multi-
variate analysis techniques were employed to analyze
This survey is particularly
the results.
important
from our point of view, hence some of the general
conclusions are listed as following:
-- The study concluded that physical factor of highway noise
is not by itself a good prediction of experi-
enced annoyance with freeway noise.
In interviews with
more than 300 residents living within sight of a
freeway, 70% of upper socio-economic
living in an area of little
freeway noise experienced
annoyance, while only half of the
noisiest area did so.
Yet the
four times as noisy as the
class residents
residents of the
second area is almost
first one.
Hence higher
socio-economic groups are more sensitive to noise,
while modest living areas complain less
noise,
and some
are cheaper
about freeway
actually are pleased that nicer homes
(supposedly) near the freeway.
-- The interview study began with the assumption
that living near a freeway has both advantages and disadvantages.
Statistical analyses, however, indicated
that residents
judge their living situation in four
distinct ways:
convenience, attractiveness, intrusion
(including odor and vibration, as well as noise),
and
necessity for handling the existing traffic volume.
-- Two major values, speed and perceived convenience,
especially convenience to leisure activities,
be related to noise
work is
socio-economic level of the
-- Attractiveness
virtue, but
for women
This is true
is second.
to
For men convenience
annoyance.
considered a second virtue;
ence to shopping
appear to
conveni-
regardless of
area.
(view of the road)
is in part individual
is an important
judgment.
-- Several features of the physical environment enter
into judgment of urban highways--distance
to highway,
lack of visual dominance of the highway, and the presence of intervening features
Features
(even surface streets).
relating to judged intrusiveness include lack
of landscaping and high noise
level.
-- It is clear from these results that it is not
the actual noise level, but the
total situation, in-
cluding attitudes towards highways and freeways in
general which leads to express
These
findings
our present study
problems.
annoyance with noise.
are very relevant to the approach of
towards highway location and design
It may be recalled that we had put the free-
way noise prediction problem in the larger context of
highway location and design problem, the
aim being
to
design and build good highways with better control over
their environmental
And noise pollution is
impacts.
but one element in the array of environmental values.
study mentioned
The BBN
search, because
lem, that these goals
conflict, and
on
these
goals.
It
It
strongly
niques
are many
are amorphous, overlap
further
regoals
is a
indicates the
and
different values
indicates
people's utility
a particular goal
our
highway location design prob-
different actors put
formation regarding
ing
relevant to
that there
it indicates
to be considered in the
is
above
that getting
regard-
and value
difficult problem at
need
for
scientific
in-
best.
tech-
to obtain people's utility for a particular goal
in the context of a broader set of overlapping goals,
for highway location-design problem.
B.
APPROXIMATE NOISE LEVELS
FOR VARIOUS LAND USES:
After this overview of the complexities involved in
getting people's reaction to highway traffic noise, following noise levels are proposed, for various land uses,
for the purpose of this study.
considered as tentative,
These levels should be
and point of departure, in
getting a feel for noise pollution impacts of various
design alternates, as they are generated.
By comparing the predicted levels of noise from
highway design variables,
to the proposed levels, one
could get a better understanding of the
causes of complaints,
in many
instances.
nature and
For example,
74
it may help in the analysis of
is
the causes of
complaint;
it really noise pollution about which people are
complaining, or are there other aspects of a highway
Such under-
location-design that are causing problems?
standing could lead to opening up areas of negotiation
between the highway designers and the community, which
in turn could lead to a meaningful trade off analysis.
Such understanding of trade offs
is even more crucial in
multiple use of highway right-of-way, and joint development projects.
It should be also pointed out that
lack of complaints in an area should not be construed
as absence of noise pollution;
a noise nuisance has to
be very great before most people will take it upon themselves
to make a formal
complaint to authorities.(6)
Further, probably in many cases the highway noise problem could- have been avoided without too much difficulty,
if the
designers and decision makers had been aware of
the noise
bility
impacts of design variables.
of noise
impact guides the highway designer
should aim at reducing and controlling
could be controlled.
the
all the noise that
It is easier to control noise at
highway design state, than after
"Prevention is better than cure."
aims
With availa-
completion stage.
It is with those
in mind that the tentative acceptable
proposed.
levels are
It should form a starting point in the noise
impact study of various
design alternatives;
the final
design will have to be evaluated and selected in the
7 ci-
context of a broader trade-off analysis of all
relevant goals
involved.
For the purpose of this
study we adopt the desired noise
BBN.
Similar noise
London Council (8)
recommendations.
the
levels recommended by
levels are proposed by Greater
incorporating Wilson Committee's
(9)
However, BBN recommendations
cover a wider range of conditions, and it is appropriate to adopt their recommendations for uses in the
United
States.
Table V-l-A shows the approximate noise
residential areas during the nighttime.
of typical conditions
in rural and
low,
are included.
levels for
A wide
It is
variety
obvious that
suburban areas the background noise
is
and with increased density various neighborhood
noises
lead to a higher indoor noise level.
Air-
conditioned buildings such as hotels and luxury apartments, usually have noticeable indoor background noise
due
to the ventilation systems;
ments
and non-luxury apart-
and hospitals usually have outdoor noise
intrusions as well as some noisy indoor activity.
The
approximate nighttime noise levels in Table V-1-A
are based on single or multiple occupancy of buildings
and on relative density of the area.
The
approximate desired noise
residential buildings are
levels for non-
listed in Table V-1-B.
The
functional uses of these places are usually related
to the quality of listening condition that should
76
prevail there.
The
list is illustrative
tional areas may be placed in the
their acoustic similarity.
and addi-
list on the basis of
The noise levels shown ap-
ply to those times when the buildings are in use;
mostly- for daytime uses,
e.g.,
but some
for evening uses,
concert halls, auditoriums, etc.
Table-V-1-A
Approximate Nighttime
Background Noise Levels
for
Residential Areas:
Indoor Noise
Level (dBA)
Situation
1.
2.
3.
4.
5.
6.
Single occupancy dwellings in
low density population area
(rural or suburban):
31
-
36
Single occupancy dwellings in
medium density population
area:
36
-
40
Multiple occupancy dwellings
in low density population
area:
36
-
40
Multiple occupancy dwellings
in medium density population
area:
39 -
43
Single occupancy dwellings,
hotels, luxury-apartments,
or hospitals in high density
population area:
40 -
45
Multiple occupancy dwellings or
non-luxury apartments in high
density population areas:
43 -
48
Notes:
1.
To the indoor noise levels
12
listed above add
dBA for open-window condition, and 20 dBA
for the closed-window condition, respectively,
to obtain equivalent outdoor noise levels.
r
2.
Increase
Table
3.
the
?
nighttime noise
V-i-A by
the
a.
for day-time =
b.
for evening
For
this
=
study,
levels of
following amounts:
8
dBA
3 dBA
time periods
are
defined
follows:
Nighttime
--
Midnight to'6 A.M.
Daytime
--
6 A.M.
Evening
--
8
to 8
P.M.
P.M. to Midnight
Table V-i-B
Approximate
Desired
Background Noise
Levels
in Non-
Residential Buildings:
Indoor Noise
Uses
1.
Levels
Concert halls, opera houses,
large auditoriums (excellent
listening conditions required) :
2.
3.
4.
26 -
31
required):
31 -
36
School class rooms, libraries,
private offices, small conference
rooms (good listening conditions
required):
36
-
40
40 -
45
-
50
Theatres, recording studios,
large conference rooms, school
auditoriums, large meeting rooms
(very good listening conditions
Large
shops
offices, restaurants, retail
and stores, etc. (fair lis-
tening conditions required):
5.
(dBA)
Lobbies, cafeterias,
work areas, drafting
ness machine
areas,
laboratory
rooms, busietc.
(Moderately
fair listening conditions acceptable):
45
as
78
Note:
To
the
levels
listed
above,
12
dBA for
open-window condition, and
20 dBA
for the
closed-window condition,
add
C.
indoor noise
respectively,
to obtain
outdoor noise
levels.
the
equivalent
AMBIENT NOISE:
People
tend
the background noise
noise
was
sounds,
be
If
the
or if its levels are
to
the
of
considered objectionable.
intrusive
people
noise
gested
the
traffic noise.
distinctive
it will be noticeand
community
noises.
it
it might
is possible
create
It has
An often
quoted
that
consciously or
also been
that pleasing background noise will
unwanted
new
In order to mitigate the
to expressways
unconsciously background
has
the
considerably higher than
from expressways,
living close
before
new noise
"ambient" levels,
nearby members
noise with
intruding
that was present
introduced.
the background or
able
a new,
to compare
often
example
sug-
mask
is
that
of traffic noise abatement with installation of fountains. (10)
Thus, in evaluating the effect of new
highway noise on a community, it is necessary to know
the
background noise
existing
levels.
Comparison of
existing noise with the expected new noise level will
indicate
noise
the
attempts at
lowering the
predicted
levels.
In order
noise
need for
to provide
information regarding
background
levels along the proposed highway route some spot
79
TABLE V-2
ESTIMATE OF OUTDOOR BACKGROUND NOISE BASED ON
GENERAL TYPE OF COMMUNITY AREA AND NEARBY
AUTOMOTIVE TRAFFIC ACTIVITY
APPROXIMATE
OUTDOOR
BACKGROUND
NOISE LEVEL
(dBA)
CONDITION
rural;
1.
Nighttime,
2.
Daytime, rural;
3.
Nighttime,
no nearby
traffic of
concern
no nearby traffic of concern
suburban;
no
nearby traffic of
29
34
con-
cern
34
4.
5.
Daytime, suburban; no nearby traffic of concern
Nighttime, urban; no nearby traffic of concern
39
39
6.
Daytime, urban;
7.
8.
Nighttime, business or commercial area
Daytime, business or commercial area
9.
Nighttime,
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
no nearby traffic of concern
industrial or manufacturing area
44
44
49
49
Daytime, industrial or manufacturing area
Within 300 ft of intermittent light traffic route
Within 300 ft of continuous light traffic route
Within 300 ft of continuous medium-density
54
43
49
traffic
Within 300 ft of continuous heavy-density
traffic
300 to 1000 ft from intermittent light traffic
55
route
38
300 to 1000 ft from continuous light traffic
route
300 to 1000 ft from continuous medium-density
traffic
300 to 1000 ft from continuous heavy-density
traffic
1000 to 2000 ft from intermittent light traffic
1000 to 2000 ft from continuous light traffic
1000 to 2000- ft from continuous medium-density
traffic
1000 to
2000 ft
from continuous
4000 ft
4000 ft
from
from
44
50
54
34
40
46
heavy-density
50
traffic
to
to
59
intermittent light traffic
continuous light traffic
30
36
23.
24.
2000
2000
25.
2000 to 4000 ft from continuous medium-density
traffic
2000 to 4000 ft from continuous heavy-density
42
traffic
46
26.
830
field measurements
are expected and desirable.
It is
not economically practical or necessary, however, to
make
a complete acoustic background study along
entire route.
On the basis of extensive
the
field measure-
ment data, for various living and working conditions,
BBN have recommended the representative noise levels
shown in Table V-2.(11)
The
first 10 conditions listed
under Table V-2 may be used when there is no definite
knowledge or description of an area in terms of
actual proximity
to traffic, while conditions
may be used when an area can be placed
the
categories.
its
11 to 26
in one or more of
In case several conditions apply, the
highest background noise level
is
to be
selected.
values shown in Table IV-2 will give a fair,
The
representa-
However, these are
tive background to most situations.
averaged values, and no specific situation should be expected to conform exactly to the given values.
that Table V-2 is not to be
used to estimate
Note
the noise
of a new highway, but only to estimate in a general way
the background noise in an existing situation where
traffic
(near or far) influences
Acceptable noise
the background noise.
levels shown in Tables V-1-A and
V-1-B, along with background noise
Table V-2,
levels shown in
will help in establishing noise goals
area with which the expected noise
for an
levels from a pro-
posed highway design can be compared.
This process is
incorporated into noise prediction guides, and explained
in the next
chapter.
CHAPTER VI
Noise
The
Prediction Process -Noise Contours:
one
levels
and V
respectively.
relationships
in
were
In this
to
reaction
in
analyzed
chapters
guides,
to be
IV
these
synthesize
chapter we
noise prediction
into
levels and highway
hand and people's
other,
on the
noise
porated
noise
relationships between
variables on
design
Development of
incor-
the highway design process.
Noise
in
carried out
prediction process will be
three phases:
A)
Establishment
in
B)
the
of
tentative noise
goals
for
land uses
corridor,
highway
Development of noise
contours
from the
highway
design
variables, and
C)
Comparison of noise
levels
to
study
explore noise
the
goals with the
noise
predicted noise
the
severity in
control measures and the
area, and
trade-offs.
Following is the outline of these phases:
ESTABLISHMENT OF NOISE
PHASE-A:
1.
Identification of land uses and activities in
the highway corridor*.
side of
GOALS:
The width of this
the highway would be probably up
corridor on each
to 1500 ft.
to
*This could be shown on the regular highway base
A plan on a scale of
plan used for preliminary design.
1 inch = 100 ft. seems quite adequate.
81
2000 ft.
for most of the freeways.
This
posed from the Case-Study experience.
The
additional width can be covered.
range is pro-
Where needed,
land uses may be
identified through conventional colour codes,
or some
other convenient way.
Post the tentative acceptable noise levels
2.
for
various activities from Table V-1-A and Table V-l-B.
Special note
should be made of the noise
sensitive spots.
sensitivity gained thus by the designer, can be
The noise
incorporated into generation of the alternative highway
designs.
Noise reconnaissance survey.
3.
trips, maps, and other information
Through field
sources, socio-economic
characteristics, general insulation characteristics of
structures
(presence or absence of air-conditioning),
tion of tall
loca-
structures, general topography, etc. may be
studied.
Also, existing noise levels may be established with
the help of Table V-2;
this may be augmented with some spot
noise measurement in the field.
a noise measure
The convenience of dBA as
is of substantial value, as
it can be read
directly from noise level meters, and avoids complicated
noise measurement and calculation procedures.
noise measurement would be analogous to
more
convenient than)
could be
Such spot
(but probably
field borings for soil
samples, and
incorporated into highway design process, when-
ever needed.
In this survey existing sources of noise
from
as well as other than traffic
traffic on existing streets
sources will be
On the basis of this
identified.
survey
existing noise levels will be posted, along with acceptA color code may
able noise levels for each land use.
be used
for this purpose.
4.
levels with the
Compare the acceptable noise
existing levels to establish
"theoretical" extent of
existing noise severity in each section.
pared with actual perception of
This may be com-
"noise pollution" by the
people in the various segments of
the area.
Various tech-
niques such as contact with community leaders,
surveys,
experts' judgment
sample
From the
can be employed.
approach taken in this study towards
highway location de-
sign problems, community participation is an essential
part of
the design process from the
initial stage. (2)
These techniques are not simple or completely mastered, and
research in these areas
is imperative,
if the concept of
environmental values in the highway design has
operationalized.
goals, of which
to be
People's values regarding environmental
"noise" is but one
element have to be ob-
tained for a broader trade-off analysis.
Hence,
we assume
that inference about people's preferences will be obtained
as best as possible, in the context of overall highway design process.
This analysis may indicate some clues about people's
reaction to existing noise
levels
for various activities.
This may also bring to attention of designer causes of
A
complaints other than those attributed to noise,
and
sharpen his
levels.
objectivity towards acceptable noise
Through this analysis, we shall establish
noise goals'
map.
for various land uses
and post them on base
Brief comments can also be made
PHASE-B:
'tentative
if needed.
DEVELOPMENT OF NOISE CONTOURS:
1.
For the purpose of noise prediction and subse-
quent noise
contour development divide the preliminary
highway design into segments
characteristics.
separated
of uniform design variable
For example, elevated section will be
from at-grade
section;
be divided into four quadrants
an interchange area will
(which is the case also for
the purpose of geometric design, and drainage grading).
2.
lane
Pseudo lane location:
freeway will be
The traffic on multi-
assumed on a single equivalent lane,
and all the distances will be measured from this pseudolane.
For non-uniform traffic conditions separate
pseudo-lanes will be established, and projected noise
levels will be superimposed.
This
step shall be
further
clarified in the Case Study.
Table
IV-7 will be used as a guide
in pseudo-lane
determination.
3.
be
Noise-Prediction Format shown in Fig. VI-l will
employed for noise
level prediction,
segment of the highway.
such as
grade,
for a particular
Information for design variables
volume, design speed, percent truck, percent upetc. be placed into the input column.
From the
- FIG VIH-NOISE PREDICTION
FORMAT
INPUT:
AT-GRADE
DISTANCE
loo,
VOLUME (VPH)
SPEED
(D
DISTANCE TABLE IV-2
DESIGN VARIABLES
ELEVATION
OUTPUT:
AT-GRADE
-.)
FIG. IV-6
ELEVATED
dBA
FIG. IV-6
DEPRESSED
dBA
100'
CORRECTIONS:
200'
300'
TABLE
IV-I
(MPH)
dBA (5 100'
(AT- GRADE)
400'
\J1
500'
TABLE
TRUCK %
UP-GRADE
IV -3
%
ACCELERATION
60oo
TABLE
IV-4
800'
TABLE
IV- 4
1000
PAVEMENT
NO. OF LANES
1500
TABLE_
IV-7
PSEUDO LANE
LOCATION
2000
i
HIGHWAY:
-I-
36
considered
the basic
for
guides. (3,4)
Hourly Volume
and
is
For our
designed.
Design
This
in time,
future point
a
would be
on
specific
situations
could be
used
church
one
or
uses
use
for
the
to suit
along
a
the
handbooks
However,
could
be
for
(in vehicles per hour)
For
example
The
used
for
Apply
corrections
to
the
one
could
Standard Traffic
for projection
basic
of
condition as
below:
For the given truck percentage, use cor-
a.
rections
b.
shown
For
in Table-IV-3.
3%-4% upgrade
Table
IV-4.
On
sents
almost the
add 2 dBA as shown in
interstate highways
upper range
on the mainline. (6)
of
the
a
Sunday morning,
recreation centers
volume.
and
Study.
in Case
specified hours.
for
4.
to
is needed,
is used
conditions.
route
weekend traffic
volume
capacity
facility
traffic volume on
the
could use
Engineering
traffic
traffic
Design
also
(base period),
the
side.
conservative
the
normally
normally available
hourly volume
future date
and
governed by AASHO
present
for which
purpose
for
Hourly Volume
is
(ADT) and
Traffic
for both the
(DHV),
is
volumes are
Traffic
of Average Daily
terms
(mile per hour)
facility, and
a highway
speed
in using
exercised
Design speed
data.
specified
in
This is
condition.
Judgment should be
design
(dBA) at
for at-grade condition, from Table IV-l.
100 ft.
volume
levels
noise
determine
and speed
volume
given
this
repre-
upgrade
used
87
c.
For
(on local
merging uphill
streets),
tions which result
made
as
to be
shown
or a
lanes,
set of
intersections
geometric
in acceleration,
in Table
IV-4.
exercised in applying
condi-
addition be
Proper
judgment has
acceleration correc-
tion.
d.
Pavement
adding up
to
tracting up
of
the
well,
5 dBA
to
for very
5 dBA for
interstate
type
conditions may be
if
surface.
are
assumed.
and subMost
maintained
their life,
However, pave-
the
local
condi-
The
effect of
climatic
conditions may be
if there is one,
is
slight
temporary.
These
corrections be
of Fig.
the
smooth
applied
ignored as the relief,
write
surface
warrant so.
e.
column
very
facilities
correction may be
tions
and
rough
applied by
and for the overall period of
normal
ment
correction may be
VI-l.
applied
In the
top
corrected dBA for basic
in the
line
of
correction
output column-1,
condition,
at
100
ft.
distance.
5.
Distance
condition, noise
corrections:
levels
From
at other distances
with corrections shown in Table IV-2.
of distance shown in output column-i,
be
sufficient.
column.
the
Record dBA
for
dBA
for basic
can be
obtained,
Normally the range
of Fig. VI-l,
various distances
in
will
this
6.
corrections
elevated or
For
Elevation:
the
to
applied
can be
sections
depressed
levels,
noise
at-grade
with the aid of Fig. IV-6 and recorded in appropriate output column of Noise Format.
7.
rection
Walls,
incorporated
for walls
buildings,
Chapter
noise
in
their effectiveness
mining
Table
using
discussed
As
in deterOpen
attenuation.
and topo-
spaces between buildings, heights of structures,
all
graphy
geometric
to forming
add up
the
and
areas
much known in
these
areas
first predict
design variables,
attempt
to
and
and
expressway traffic
unfortunately there
plot the
observing
then
further modify
noise
our
not
in the Case
levels
the
is
systematic
in
be incorporated
to
We shall therefore
noise prediction guides.
Study
And
concern.
of
configuration and
between the
'line-of-sight' relationship
IV-5.
intervening
involved
variables
are many
there
IV,
applied to
can be
of
and
design,
straightforward.
not
is
however,
column,
effectiveness
of the
Evaluation
in
out-put
values recorded in
the
in highway
in urban areas),
(not operational
woods
cor-
Buildings:
and Intervening
Woods,
from highway
overall
evaluation of noise
situation
severity,
by exercising judgments and making educated guesses.
Wherever needed, cross-section sketches will be plotted
to investigate the
and the points of
used
of
to account
'line of sight' between the
interest.
for partial
Further, Table
exposure
to
analysis along with discussion under
expressway
IV-6 could be
freeway.
This
kind
"Effects of Acoustic
89
Barriers
and Elevation"
insight into
the noise
in Chapter
IV,
attenuation
might
effects
give
of
us some
intervening
buildings.
The
tances,
in
the
"noise
final
corrected noise
for a particular
output
levels at
segment of the
column of Fig.
VI-1
various
dis-
highway, recorded
are used
in plotting
contours".
8.
Plotting Noise
Contours:
Developing noise
contours, on the basis of noise data of Fig. VI-l, will
enable
us
to
examine
uses under the
the noise
actors
environment,
in
the
all
the
land
influence of the highway, at a glance.
approach will- enable us
total
severity in
area,
to view
including
rather
the noise
all
impacts
activities,
than one
and
particular
on
This
the
all
location.
Such a broader approach will permit a broader trade-off
analysis.
Further in
way
right-of-way
the
study of noise
the context of multiple uses
and Joint
Development projects,
impacts all
of high-
we
need
along the route, rather than
noise estimation for one particular point of interest.
I
believe development of noise contours, as a part of preliminary highway design process
drainage contours),
(like development of
will sharpen the designer's
sensitivity
regarding noise impacts of alternate highway schemes, as
he
generates
them.
Following procedure
recommended on
Study;
the basis
of
for
developing
experience
noise
gained
contours
from
the
is
Case
90
100
For
ft.
intervals,
traffic
source of
Please
lane
a pseudo
noise
mat as before
are
shown
of
are
in MAP-2,
contours
smoothly points
the
resultant
noise
MAP-3,
Case
In
roadways
on
noise
from mainline
c.
set
of
estimates
established,
Prediction Forcross-road
for
contours,
the mainline noise
At the
Study.
and
cross-road,
quide.
equal noise
levels
IV-8,
contours,
By
decibels
joining
(dBA) ,
incorporating
cross-road,
and
as
we
get
traffic
illustrated by
Study.
cases when
contributing
contours
can be
the
previous
noise
at grid
there
to
are
more
than
two
"noise pollution",
plotted,
contours.
intersection, and
a
third
and superimposed
By
adding
joining
as
intersection
grid
as
of
dBA's
is
Noise
using
from mainline
areas),
(e.g. interchange
cross-road
over
Case
also con-
are
cross-roads
noise
using Table
added
sufficient.
Study.
and noise
superimposed
be
Case
for the
other
no
the
estimated,
levels
from
is
will
to traffic
tributing
be
there
this
In areas where
step,
Plot
required.
if
noise,
of
see MAP-1,
b.
a preliminary
area where
In an
VI-l.
Fig.
As
respective distances
for
dBA,
correct
the pseudo base
shortened
extended or
further
to
covered, which may
width may be
ft.
2000
about
the
in step-2.
determined
line
parallel
at
lines
draw
highway,
segment of
each
a.
the
again,
points
of
relevant
tours,
for the
can. be
repeated,
in the
real
case study,
1.
on
Super-impose
transparent
dicted noise
the
locations,
the
faced
of
the
situations
complex
6 to
MAPS
design;
9.
CONTROL ANALYSIS:
final
noise
(developed
contours
recommended from
the pre-
Compare
the base map.
the Case
for all
highway corridor.
note of
Make
2.
over
'A'
Quadrant
levels with the posted noise goals,
in the
uses
the
develop
conditions,
of
urban highway
overlays, which is
experience) ,
Study
in
SEVERITY AND
NOISE
PHASE-C:
an example of
faced
frequently
a variety
con-
procedure
judgment to
world situations.
is
This
roadways.
exercising
for
noise contours
final noise
get the
levels, we
noise
equal
using
the noise
severity
at
following BBN recommendations
various
(7)
as
a
guide:
It is
of less
believed that
a
"noise
few
than 5 dBA will not cause
level
serious
excesses"
complaints from
residential neighbors, along the highway route.
level
excesses of 5 to 10 dBA would represent a marginal
noise problem, and
level
onset
of
level
excesses of
to
Non-acoustic
factors,
15
10
to
20
such
as
concerted
category;
represent the
noise problem;
dBA or more
individual or
factors,
to predict
15 dBA would
to
serious
a potentially
strong
a hard
represents
excesses of
noise
lead
Noise
and
noise
would probably
community action.
social-economic and political
can modify this general evaluation of the community
reaction
by at
least
for an
offered here
gories
excesses
cate-
"average population."
This
treated as an
evaluation may be
noise
below the
'opinion' that these
indication
an
are
or
step above
one
that signify accepta-
problem, and not as specific values
VI-1
Table
Probable
Reaction
--
probably
ignored
--
marginal
range
dBA
--
onset of
problem
serious
15-20 dBA
and more
--
dBA
Excess
0-5
dBA
5-10 dBA
10-15
Furthermore,
to
Excesses
Level
of Noise
Significance
in Table VI-1:
summarized
are
values
above
The
bility.
a potential noise
of
as
freeway noise
concerted community action
expected
discussed
has
the
content of
such, the above values are
to be
and tentative guide.
the noise
trade-offs involved:
in
evaluated
considered as a provisional
Explore
people's reaction
Chapter V,
in
to be
As
total environment.
3.
noise
measures
control
In the following we
the various noise control measures.
and the
shall discuss
This should provide
us with some insight into the kind of interest groups
being
affected,
a.
and
the
Control
great many
trade-offs
at
Source:
technical
tailed treatment is
involved.
This
involves
considerations,
beyond
the
and
scope of
a
its
this
de-
Noise from engine and exhaust is most
study.
serious.
evidence that exhaust noise
There is
could be reduced by using larger and more efficient silencers,
without
engine's
reducing
efficiency, to be of any practical importance. (8)
The
noted, however,
Wilson Committee
something
can be done
in the
that while
short term to
reduce
noise of individual vehicles, the most frequent
offenders, diesel-engined buses and commercial
The
vehicles, are the most difficult to quieten.
present form of reciprocating
internal
engine may well be replaced one
combustion
day by quieter
forms of propulsion but as this is
unlikely to
happen in the near future, there seems to be a
need for intensification of research into the
reduction of noise
By
the
from engine and exhaust systems.
proper maintenance of
noise
from tire
be minimized.
the pavement
surface,
and pavement interaction
can
Expressways are generally well
maintained, but noise reduction can be advanced
as an additional argument for
of heavily travelled local
surface maintenance
roadways.
Improving
the noise characteristics of pavement surfaces
with admixtures, could be proposed as another area
of research.
As mentioned earlier, the BBN Studies indicate the definite need for improving the muffling
practices of motor cycles.
94
b.
Legal
Control:
muffling practices
ally adequate,
control of
The
of
As
autos
and there
and
is
are not
and cause of
complaints.
Again,
there
inforcement of
Traffic
control and
is
the
through
normal
room
for
legislation
route
are
gener-
legislation.
to
source
extreme
of
improvement
noise,
and re-
for motor cycles.
Management:
truck
trucks
normally directed
cases, which
earlier, the
is little scope of noise
existing vehicles
legislation
c.
mentioned
By traffic volume
planning, noise pollution
may be controlled in urban areas.
By-passes and
ring
heavy traffic
roads
on local
ways.
are
already
in
streets may be
use;
the
channelized
through express-
However, this kind of improvement is
obviously
in the context
of regional
transportation
planning.
By
careful selection
of
intersection
change points, with respect to
to
acceleration may be
land uses,
and inter-
noise due
controlled.
By encouraging free flow of traffic, on
expressway and local streets through signalizations and other
traffic control systems,
again
noise due to acceleration may be reduced.
d.
gained
Highway Design Variables:
regarding relationships
design variables and noise
Sensitivity
between
highway
levels can be utilized
95
to control the noise severity along the highway
In particular sections, elevations may be
route.
changed;
grade may be modified;
acceleration lane
may either be relocated or its design may be modified;
design speed or traffic volume may be
controlled
(not operational
for expressways
due to
present design standards, but new standards may be
evolved to consider such trade-offs);
distance
may be modified by varying curvature and alignment
(not operational in most urban areas, nevertheless
this potential may be kept in mind).
With experi-
ence the designer can develop a feel for the
range of noise reduction achievable through manipulation of design variables,and can use the optimal
combination according to the needs of a particular
section.
However, the modification in highway design
variables will have to be carried out considering
trade-offs such as
cost, aesthetic, accessibility,
The approach taken in this study,
etc.
rected to explore
is di-
the ways of improving such
sensitivity.
e.
Walls and Barriers:
Noise levels can be
substantially reduced by providing solid walls and
barriers as discussed in Chapter
IV.
A
3 ft. high
solid wall along the edge of the roadway will
reduce noise levels by 4 dBA, up to
500 ft.
from
roadway, without obstructing driver's view from
the road seriously.
Provided on an elevated
roadway it can further
improve the noise
shielding
effects.
The attenuation potentials of intervening
structures be kept in mind, considering their
height, open spaces, and line of sight considerations.
However, the
impact on the
these buildings require
due
foremost considerations,
to the higher noise severity.
could be:
consider
residents of
One approach
insulation costs for the
intervening buildings;
and consider their attenu-
ation effects for the uses behind them.
f.
Buffers and Landscaping:
Natural vegeta-
tion has some effects on noise as discussed earlier,
but the depth of planting required would not be
feasible in most urban areas.
However landscaping
along the route, while not reducing noise, may
help psychologically by improving people's perception of the highway.
g.
Land Use Planning:
The noise contours
along the route, may indicate the proper locations
for various land uses in the highway corridor.
In
case of new developments or coordination of other
development with highway design, like those envisaged in joint development projects, noise
sensitive activities such as residences,
schools,
hospitals and sound studios, etc.,
may be placed
in the shadow of other tall structures.
The
noise contours can provide a framework, in which
a system of land use
planning could be developed
from the "noise effects" point of view.
Such a
system could be further enriched with air pollution
and aesthetic considerations.
h.
Insulation of Buildings:
In joint develop-
ment projects, adequate insulation could be a part
of structure design.
ment, insulation of
provisions
the noise
In case of existing developbuildings and air-conditioning
(to keep windows closed),
severity.
Such additional
may improve
costs could be
logically included in the project cost.
But
insu-
further research is needed for estimation of
lation cost from highway traffic noise.
In many cases the extra insulation cost may
prove to be lower than changes in the highway
design variables.
In other cases
the extra insu-
lation cost, though substantial, may be justified
for preservation of crucial points of interest.
(e.g. The French Quarters
in New Orleans).
in other cases extra insulation cost may be
sidered as an integral part of the highway
Still
concost,
because people expect higher level of service, and
may put high value on reduction of noise pollution.
However, operationalization of such new
'cost'
estimation require new legislation and design
standards.
i.
Background noise:
It has been
suggested
that the annoyance produced by intrusive noise is
related primarily to the difference between the
levels of the intrusive and steady components.
A possible explanation for this
is associated
with the momentary interference the
intrusive
noise has on communication
(we occasionally miss
the punch line of a joke) ,
and is also associated
with the fact that the source of the intrusive
noise is
recognized.
It is possible
that a higher steady noise
level could result in a more
comfortable environ-
ment by inducing people to adjust their conversation
level, or their television and radio volumes
at higher levels.
Such adjustment may be also
achieved by inducing people to move closer when
they converse.
would
The occasional
intrusive noises
then not cause as great an interference
with speech communication and people would be
less
annoyed with them.
Detailed acoustic analy-
sis will be needed for this purpose, keeping the
activity type
in mind.
As mentioned earlier, a pleasing background
noise will often mask unwanted traffic noise.
Several examples are cited in noise literature to
99
illustrate the relief achieved from traffic noise
botheration by installation
Such-solutions may be
of fountains. (10)
considered in the multiple
use of highway right-of-way.
It may be
added, however, that some of the above
discus'sed measures are beyond the control of highway designer
(e.g. noise control at source) , while others
are
non-operational according to present-day design standards
(e.g. the interstate standards for speed and curvature);
still
for other measures the present policies do not
cover the cost.
Insulation cost of structure could be a
legitimate cost of highway design.
In areas where noise
severity cannot be controlled, inspite of all the
feasible
tools, either damage cost or relocation cost should be
sidered for the residents; or as an alternate
step the
areas.
route may be
(and ultimate)
completely relocated out of
These issues are relevent, and are
in significance, in the urban highway
for policy and legislative innovations
con-
such
ever increasing
locations.
The need
for dealing with
these issues cannot be overemphasized.
Following is the summary of noise prediction and
control process.
The highway designer could use this
summary for a quick reference;
the details of a particu-
lar step could be referred to in the above discussion.
100
Summary
of Noise
Process
Contour Development
GOALS:
ESTABLISHMENT OF NOISE
PHASE A:
1.
Identify
2.
Specify
and Table
V-l-B.
3.
Study
land uses.
tentative
existing
and
Table V-1-A
level;
noise
noise
field measurement
(and spot
and Noise
Prediction,
environment,
Table V-2
community interaction
process).
Establish noise goals and post on base map.
4.
PHASE
DEVELOPMENT
B:
variables.
design
2.
Locate pseudo-lane;
3.
Place design
at
Apply corrections, as shown
and place dBA
the
of
outout
at grade
data determine
in the correction
condition at 100
ft.
in
the
column.
corrections, Table
IV-2.
Fig.
IV-6.
5.
Apply distance
6.
Apply
7.
Apply barrier correction
elevation
corrections;
Table
IV-5,
IV-6.
8.
in
from speed-volume
4.
of
input-column
in the
ft.
line
Table
IV-7.
100
column,
top
Table
variables
Format;'
'Noise Prediction
dBA
CONTOURS:
the highway into segments of uniform
Divide
1.
OF NOISE
Plot noise
contours
output column of
using
corrected noise
'Noise Prediction Format'.
levels
First
101
from mainline
cross-road.
at
Repeat
NOISE
1.
ft.
intervals,
Add decibels
(Table IV-8).
PHASE-C:
100
at grid
then superimpose
intersections
for more than two
SEVERITY AND
Superimpose
noise
from
roadway
conditions.
CONTROL ANALYSIS:
contours over
the
base map.
Compare predicted noise levels with posted noise goals.
see
2.
Note
3.
Explore
items
3(a)
noise
to
severity,
Table VI-l
and Chapter V.
noise control measures and
3(i)
in PHASE-C,
For each alternate
highway
trade-offs;
discussions.
design, noise
contours
be developed, noise severity be analyzed, and the
measures and
trade-offs be
explored.
The
control
sensitivity re-
garding noise impacts of alternate schemes gained thus
could be used as an input into the overall highway
design process.
And in the
location
framework of broader impact
analysis, preferred design alternate could be developed.
This brings
theoretical
the
close
of
Part-I,
and our
noise
In this analysis attempts were made to
effects
impacts, in a broader
process.
to the
analysis of noise measurement, prediction and
control measures.
place
us
as
but one
of the
environmental
framework of highway location-design
The use of noise prediction guides will be
clari-
fied and demonstrated by a Case Study, in Part II of this
research,
which
follows.
102
PART
CASE
TWO
STUDY
103
{04
NOISE GOALS dBA
INDEX
r(DL-.....
NOISE GOALS dBA
(OUTDOOR)
(OUTDOOR)
Ow*
C.*
. .
ojw *
C.*
55
63
60
68
COURT 40
54
RESIDENTIAL
MEDIUM DENSITY
61
69
COMMERCIAL OFFICES a STORES
RESIDENTIAL
HIGH DENSITY
65
73
LIGHT
SCHOOL
(a) CLASS ROOMS
(b) AUDITORIUM
50
45
58
53
PARK
45
53
CHURCH
*
INDUSTRY
QW. - OPEN WINDOW
C.W.-- CLOSED WINDOW
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___J
CHAPTER-VII
Case-Study
In
this
part we
shall
clarify
and
demonstrate
discussed
application of noise prediction techniques
Part-I
sis
of this
of the
levels
study.
relationships
trail was
This
clarified the
range
presented
in
for noise
have
Route-93
way
selected a portion of
for Case-Study.
construction
in Medford
The
used
as
Charles
three
contour
some
analy-
and noise
of their
appli-
relationships and
development process
AND DESCRIPTION
just
Inner-Belt
south of
(see Plan-1,
Project Plan
is
shown
in Plan-2
for
A.
& Associates,
'hypothetical' (3)
this
in Boston
the
study
alternates
to the
end
of
Mystic Valley Park-
(2)
through
Inc.
Interstate
link when completed
Location Plan
a base map
Maguire
the proposed
The proposed
connect the proposed
present
of
made
in
Chapter VI.
PROJECT LOCATION
will
between design variables
a preliminary
pointed directions
We
after a preliminary
(dBA) ,
cation.
A.
Actually
the
).
.
This plan
is
courtesy of
I have
using the
considered
same
base
map;
ALTERNATE-I
Mainline (1-93) at-grade; Y-Line
(Fells Parkway including the portion called McGrath Highway adjacent
to Quadrant 'C'), elevated.
106
107
Alternate-II
:
Mainline
Alternate-III
:
Mainline at-grade with 3 ft.
high
solid
side walls; Y-Line elevated.
The grade
shown
in
profiles
Fig.
elevated;
for the hypothetical
Y-Line
at-grade.
alternates
are
VII-l.
We have considered only two basic elevation conditions,
i.e. Mainline at-grade, and Mainline elevated.
A third
variation Mainline depressed was not considered due
verse soil,
and engineering
prohibitive costs.
to ad-
considerations, and subsequent
Consequently we considered Mainline at
grade with 3 ft. high side walls
Though the alternates
as the third alternate.
considered are
'hypothetical',
they resemble the real world situations, and provide good
examples for application of noise prediction techniques.
B.
NOISE PREDICTION AND CONTOUR DEVELOPMENT PROCESS:
We shall use the guides
this
purpose
1.
as
recommended in Chapter VI,
for
following:
PHASE-A: Establishment of Noise Goals:
The study area is divided into Quadrants A,B,C and
D*,
and the land uses are identified as shown in
Plan-2.
Noise Goals
for land uses in each quadrant are
specified as following:
*Analysis of quadrant 'D' was considered to be a
repetition and therefore not undertaken.
108
a.
QUADRANT-B
-
It is primarily residential,
land uses in-
clude Land Use-1, Residential, medium density
(relatively) and Land Use-3, School.
Land Use-l
-
--
-
Residential
(medium density):
levels
Tentative noise
for this
use
(multiple
occupancy dwellings in medium density population
area, item 4, Table V-1-A
Indoor
are shown below.
Outdoor
(dBA)
O.W.*
C.W.*
Night
41
(mean)
53
61
Day
49
(mean)
61
69
-
For background noise
(dBA)
levels only Iable V-2
But in actual design
used in this study.
field measurements are recommended.
is
spot
In addition
the community interaction process could give us
better understanding of people reactions to existing
Background noise is
noise environment.
studied for
two categories:
i)
Within 300 ft.
traffic =
of continuous heavy density
59 dBA
(item 14,
for first two
rows of houses)
ii)
300 to 1000 ft. from continuous heavy density
traffic =
54 dBA
(item 18,
for houses beyond
first two rows)
*O.W.
open-windows;
C.W.
:
closed-windows
109
The
time,
noise
highways
values
levels
item-7
between
in
above
apply
for
daytime;
probably approximate
due
and item-9,
and commercial
and industrial
night-
the range
to presence
of
activities
adjacent areas.
=
Nighttime background noise
are
for
Noise
Goals:
The
adopted as Noise
above
Goals.
existing background noise
49
dBA.
tentative noise
It
levels
observed that
is
levels are
acceptable levels and we have
new noise level excesses.
-
44
the
lower than the
to be cautious about
Furthermore, the houses
and the neighborhood in this quadrant seems to be
of somewhat better quality than in those in other
quadrants.
Land Use-3 School
-
We shall consider school classrooms and
school auditorium.
Table
V-1-B are
Indoor
Tentative
given
noise
(dBA)
Outdoor
(dBA)
O.W.
C.W.
:
38(mean)
50
58
Auditorium
:
33( mean)
45
53
Background Noise:
300 to 1000
from
below.
Classrooms
-
level
We use
item 17,
Table V-2
ft. from continuous medium density
traffic = 50 dBA.
We observe that for classroom
110
the background noise is
equal to specified level
for open windows, and lower than specified level
for closed windows.
For auditorium with open
windows background noise is
5 dBA higher than speci-
fied level, but lower with closed windows.
auditorium it is reasonable to
For
assume that closed
windows condition would apply.
Values shown under the
-
tentative noise
levels are adopted as Noise Goals for school.
b.
QUADRANT -
C
Residential use in this quadrant is
subdivided
into:
Land Use-1;
Residential, medium density,
Land Use-2;
Residential, high density
Units in the
Other uses
'Project-Housing').
include,
Land Use-4
Church
Land Use-5
Commercial
Land Use-7
Park.
Noise goals
(this includes
for each use is specified as fol-
lowing:
Land Use-l;
This
is
Residential
(medium density)
same use discussed in Quadrant-B and
same noise goal would apply.
111
Land Use-2;
-
Residential -
(high density):
levels for this use
Tentative noise
(multiple
occupancy dwellings or non-luxury apartments
in high
are
density population areas, item-6, Table V-1-A),
shown below:
Indoor
(dBA)
Outdoor
(dBA)
O.W.
C.W.
Night
45
(mean)
57
65
Day
53
(mean)
65
73
-
Background noise
is studied for two categories,
using Table V-2,
item 13, within 300
ft.
of continuous medium
55 dBA
density traffic
300 to 1000
item 17,
density
ft.
traffic
=
For nighttime, item 9 area is
from continuous medium50 dBA
industrial or manufacturing
=
used as guide:
49 dBA
It is observed that the existing noise levels
are below specified level even with open window conditions.
Hence we have to be careful about new noise
level excesses.
-
We adopt the values shown under tentative noise
levels as Noise Goals
for this use.
Land Use-4; Church:
-
For
the Rectory part of church, noise
for Use-l -
Residential is
adopted.
goals
112
-
below
For
Day
33
-
as well
ft.
It is
of
specified levels
-
Values
as
even
Land Use-5
;
Day
-
For
church we use
for background noise
noise prediction
item
11,
light
Table
V-2,
later
within
route =
traffic
levels
43 dBA.
are below
with open windows.
tentative
for
noise
levels
are
church.
Commercial:
Tentative
noise
are
shown
Indoor
(dBA)
43
53
for
shown under
Noise Goals
table V-1-B)
45
current noise
adopted as
-
C.W.
Note:
intermittent
observed the
shown
(dBA)
O.W.
traffic both
Background noise,
on.
Outdoor
Background Noise:
estimation,
300
(dBA)
(mean)
Sunday morning
are
V-1-B)
(item-2, Table
Indoor
levels
noise
church tentative
(mean)
Background noise
levels
for this
use
(item 4,
below:
Outdoor
(dBA)
O.W.
C.W.
55
63
(use item--13,
Table
V-2)
=
55
dBA.
1 '5
Existing
noise
level
is not more
shown
under
tentative
than
specified
level.
-
Values
adopted
is
terion
is
difficult to
for all
types
levels
and
and
than those
be
tolerated
as
relaxing on
benches
For conversation,
able
while
considered
to
at
mended
could
comfortable
converse
could
5
use
active
place.
59
ft.
existing
The
such as
for passive
and
levels would
recreations
Interference
as criterion
other
voice
It has
voice
level,
for passive
But
in
Existing noise
levels
level,
been
recom-
noise one
with a
separa--
"Foss Park"
and
Hence probably higher traffic
the
should
recreation one
the
(baseball, basketball
interfere with
Level
(4) ; people
at normal
distance.
criteria.
such
conversation.
Speech
Hence
seems
baseball,
higher noise
at normal
cri-
and such criterion
46 dBA traffic background
(5)
this
sports
would not
=
hear each
that at
tion of
sports
swimming,
noise
type considerations
activity
basketball
be
parks,
general
(to my knowledge).
For active
been
have one
of
relevant.
has
are
Park:
not available
noise
levels
as Noise Goals.
Land Use-7;
It
noise
swimming) take
noise
levels
activity.
(use item
14,
Table V-2)
dBA.
We
shall
keep
these points
comparison with predicted
noise
in mind,
levels.
later
for
114
c.
QUADRANT-A
Primarily, uses
in this quadrant include
industry,
truck services, transportation companies, large warehouses, involving heavy truck traffic and railroad
Light Industry.
We term them as Land Use-6,
yards.
In addition, there
is a District Court in this
quadrant, indicated by Land Use-8.
Land Use-6, Light Industry:
-
Tentative noise
Table V-l-B, are as
levels, using item 5,
following:
Outdoor-dBA
Indoor-dBA
48
-
(mean)
Background noise
-We
C.W.
60
68
(use item 14,
shall adopt above
Noise Goals
0.W.
Table V-2)
=
59 dBA
tentative noise levels as
for this use.
Land Use-8, Court:
-
Tentative noise
levels, using item-2,
Table V-1-B are as following:
Indoor-dBA
34
-
(mean)
Background noise
Outdoor-dBA
O.W.
C.W.
46
54
(use item-14,
Table V-2)
=
59 dBA
1 15
-
Tentative noise levels shown above,
However, it should be
adopted as Noise Goals.
noticed that existing background noise
ally,
above analysis one
existing noise levels
levels
the specified
and probably no serious noise
problem exists in the area at present.
to be cautious about the noise
expressway
already
could conclude that gener-
are not above
land uses,
for various
is
for court.
5 dBA higher than the specified noise
From the
are
Therefore, one has
level excesses from the new
traffic.
However, though we have used Table V-2 as a guide
existing background noise levels,
these
for
values may not be
adequate, and the need for spot field measurements along
with some community interaction is
strongly felt, and recom-
mended.
The Noise Goals
for various
and posted on Plan-2.
land uses
Since noise
are summarized
levels shall be predicted
for peak hour traffic conditions, only daytime Noise Goals
are posted
for comparison.
Whenever required, this
analy-
sis could be extended for nighttime conditions, using
traffic volume,
2.
PHASE-B:
and noise goals
for nighttime.
Development of Noise Contours
For noise predictions Mainline
(1-93)
is divided
into two segments of uniform design variables: (a).
first segment covers approximately stations. 83+00 to
112+00,
including Quadrants B & C; (b).
The
second
The
116
Quadrants
A
& D.
First we
a.
& C,
B
rants
including
112+00 to 135+00,
segment covers stations
for
covering Quad-
segment
consider the
alternate designs,
the three
as
following:
see Fig.
(Note:
Mainline
design variables
Format No.
Noise
dBA,
recorded in
then
used to
are
in
put
plot noise
contours
and corrected
These values
the output column.
the
from
of
input column
the
applied
corrections
1,
Profiles)
Grade
for
VII-l
elevated.
Y-Line
at-grade:
Mainline
ALTERNATE-I
are
Mainline
traffic as shown in MAP-l.
It should be noticed that design hourly traffic
volume
for
evaluate
Y-Line
No:
2
1985
are used.
the noise
severity
design variables
are
at about worst
sections of roadway.
transition section
In
the
output
is
columns
corrected noise
levels
elevated conditions.
noise
contours
the roadway section
At a height of 20 ft.
transition section between the
Format
(for
Format No:3
will be considered fully elevated;
to
conditions.
recorded in Noise
(for Quadrant-B) and Noise
Quadrant-C).
us
enable
This will
there will be a
elevated
at-grade and
Approximately mid-points of the
shown
on all
of Noise
are
These
from Y-Line
Formats
shown
for
values
traffic
maps.
relevent
and No:
2
at-grade
are
as
No:
used
shown
and
to plot
in MAP-2.
3
- FIG
NOISE PREDICTION
FORMAT
INPUT:
NO: 1
(QUADS.
B&C
see MAP-l)
DESIGN VARIABLES
ELEVATION
AT-GRADE
DISTANCE
100,
VOLUME (VPH)
(MPH)
TRUCK %
UP-GRADE
ACCELERATION
NO. OF LANES
HIGHWAY:
:
TABLE
IV-I
50
<3
NONE
TABLE
IV-3
8
dBA ()
(AT- GRADE)
= 73
3 dBA
76
TABLE
IV-4
+
0
76
TABLE
IV- 4
+
+
TABLE
IV-7
OUTPUT:
0
DISTANCE
NC.
@
TABLE IV-2
ELEVATED
_AT-GRADE
dBA
dBA
100'
76
200'
72
300'
70
400'
68
500'
67
600'
66
800
64
1000'
62
1500'
60
2000'
58
0
76
0
76
PSEUDO LANE
LOCATION
40 ft
from ed
Y-LINE
DE RESSED
dBA
Hj
__1I
MAINLINE: (1-93)
MAINLINE AT-GRADE;
@
100
+
NORMAL
PAVEMENT
ALT.-I
I
12
%
CORRECTIONS:
10',000
I
SPEED
VI-I--
ELEVATED
-4MA
-
1C
S
:B
& C)
*RE
(NU
D
AN
*)t
rRAFFIC
NOSA
OTUSFRMMILNA
: Y-LINE ELEVATED)
*u
-0LENT-
MILN
TGAE
mYv*ll.LAwIL
0000,
CT
SICP
Ms3
2100
S0
(tic)
(iU
1200(120)
srs
2
n MiLa
,e
se
0
-
--
--
-
-l
too
~so
-(I.
zig*
)k3 -7
n
@"
0
9'93
T-~~
a4A
-
x
-~
---
-I
-
I
VA
S104AGE
&*1
WeA
RIVER
Nr]
-fact
OEMBY
Noll
-
5TC
-
-0
-
-
-
0
- FIG
NOISE PREDICTION
FORMAT
INPUT:
DESIGN VARIABLES
NO:
(QUAD. : B,
ELEVATION
AT-GRADE
DISTANCE
100,
VOLUME (VPH)
7965
(MPH)
TRUCK %
I
%
ACCELERATION
TABLE
dBA (®i)100
IV-t
(AT-GRADE)
40
TABLE
IV-3
>3
YES
(LINE
-F
PAVEMENT
NORMAL
NO. OF LANES
WIDE
15 0'
(D
DISTANCE
=
dBA
70o
+
3
HIGHWAY:
:
-
@
FIG IV-6
DEPRESSED
dBA
dBA
100'
80
72
200'
76
72
300'
74
72
400'
72
72
TABLE
IV-4
+ 2
TABLE
IV- 4
+
71
71
600'
70
70
800'
68
68
75
I
+
TABLE
IV-7
500'
73
5
0
PSEUDO LANE
LOCATION
Y-LINE (FELLS PARKWAY)
MAINLINE AT-GRADE; Y-LINE
ELEVATED
-
80
1000'
66
66
1500'
64
64
2000
62
62
80
48 ft.
from
edgie
-
ALT.-I
@2
TABLE IV-2 FIG. IV-6
AT-GRADE
ELEVATED
H
12
UP-GRADE
2
see MAP-2)
OUTPUT:
CORRECTIONS:
i
SPEED
VI-I---
-
T_
~1~
- FIG
NOISE PREDICTION
FORMAT
INPUT:
DESIGN VARIABLES
ELEVATION
ATGRADE
DISTANCE
100,
VOLUME (VPH)
5680
I
SPEED
(MPH)
NO: 3
(QUAD. : C, see
%
ACCELERATION
IV-B
(AT-GRADE)
40
>3
YES
TABLE
+
IV -3
+
TABLE
NORMAL
NO. OF LANES
HIGHWAY:
ALT.-I
100N tE
wide *
= 69
TABLE
IV-7
TABLE IV-2 FIG. IV-6
DISTANCE
DA
AT-GRADE ELEVATED
(ft)
dBA
dBA
100'
78
70
200'
74
70
300'
72
70
400'
70
70
FIG. IV-6
DEPRESSED
dBA
T '7
f'4/NAT re T
500
69
69
600'
68
68
800'
66
66
1000'
64
64
1500'
62
62
2000'
60
60
0
78
LINE F PARTIT
H
74
2
+ 4
TABLE
-5-+5
@2 -
72
3
IV-4
IV- 4
OUTPUT:
dBA (i5) 100'
[TABLE
'A
PAVEMENT
MAP-2)
CORRECTIONS:
12
TRUCK %
UP-GRADE
VI-
T\T:tTh
etT
+ 0
PSEUDO LANE
LOCATION
Y-LINE (FELLS PARKWAY)
: MAINLINE AT-GRADE: Y-LINE ELEVATED
78
40 ft.
from
edqe
III-
","-I
-p..
45
S30o
-2
AMAP
\
\&RK~§
(
~SUPERIMPOSED
ALTERNATE-I
QUADRANTS
NOISE
& C)
:B
CONTOURS
FROM
(MAINLINE AT-GRADE
-Y-LINE
TRA FFIC
Y-LINE ELEV ATED)
i
wevv
CPw 0
x.
os
eorn
uo
---
-looa
Il
ff
I0
p a l
gI N G
4vt
INTRS
V4924
7
0pu
q70
U
0
-J
PCo
1.1
70
0
A
ARE
1.n
x
n
a
ROU
L
I A
MAP - 3
( QUADRANTS B
& C )
RESULTANT NOISE CONTOURS FROM MAINLINE
~ 9 Y-LINE TRAFFIC
ALTERNATE-I
:
&
(MAINLINE AT-GRADE: Y-LINE ELEVA TED)
Itss
oI
*
*Zsec*i*
no.
4v
"
-- -L
Z
op.P-
*
3u
to-
#
"00
123
At the grid intersections of the superimposed noise
(using Table-IV-8),
contours, dBA's are added
and
equilevel dBA points are then joined to develop resultant contours for ALTERNATE-I, as shown in MAP-3.
This
is accomplished conveniently with the use of transparent overlays.
It may be pointed out that the 'left hand traffic
move'
from Fells Parkway to 1-93,
South Bound is accom-
plished through Line-F-, envisaged to be on a third
level.
It is
assumed that this
condition would result
in additional acceleration and grade climbing by traffic
on Line-F, and has been considered in Noise Format No:
ALTERNATE-II:
2.
MAINLINE ELEVATED: Y-LINE AT-GRADE.
Using same procedure, Mainline traffic noise is estimated in Noise Format No:
4,
estimated in Noise Format-5
Format-6
and Y-Line traffic noise is
(for Quadrant-B) and Noise
(for Quadrant-C).
Again, first noise contour for Mainline are plotted,
then noise contours for Y-Line are superimposed and dBA's
are added at grid intersection, and resultant noise contours are developed as shown in MAP-4.
(The process is
performed on overlays, and only resultant noise contours are shown here).
In ALTERNATE-II, Line-F
(left turn move from Fells
Parkway) is envisaged in a tunnel.
However, a substan-
tial length of Line-F will be on grade, and the slight
FIG
-
VI-I-
NOISE PREDICTION
FORMAT
INPUT:
DESIGN VARIABLES
4
(QUADS. : B&C see
AT-GRADE
DISTANCE
loo,
VOLUME (VPH)
10,000
SPEED (MPH)
ITABLE
IV-1
50
dBA
(
dBA
dBA
100
76
68
200
72
68
300'
70
68
400'
68
68
MAP-4)
CORRECTIONS:
I_
@
(D
IV-2 FIG. IV-6
DISTANCE TABLE
AT-GRADE ELEVATED
NO:
ELEVATION
OUTPUT:
FIG IV-6
DEPRESSED
dBA
100'
(AT-GRADE)
73
H
f\)
TRUCK
%
UP-GRADE
12
%
ACCELERATION
FAVEMENT
NO. OF LANES
<3
NONE
NORMAL
8
TABLE
iv-3
+
3
TABLE
IV-4
+ 0
TABLE
+ 0
IV- 4
500'
67
67
600'
66
66
800'
64
64
1000'
62
62
1500'
60
60
2000
58
58
76
76
76
-5---~.+5
+ 0
TABLE
I'V-7
PSEUDO LANE
LOCATION
76
40 f t.
from
edgre
f1
HIGHWAY:
MaINLINE: (1-93)
ALT.-II
MAINLINE
ELEVATED:
Y-LINE
AT GRAbE
VI-I --
-FIG
NOISE PREDICTION
FORMAT
INPUT:
NO: 5
(QUAD:B,see MAP-4)
DESIGN VARIABLES
ELEVATION
AT-GRADE
DISTANCE
100,
VOLUME (VPH)
7965
I
SPEED
(MPH)
IV
40
(D
DISTANCE
00)
CORRECTIONS:
TABLE
OUTPUT:
@2
TABLE IV-2 FIG. IV-6
AT-GRADE ELEVATED
dBA
100
75
200
71
300
69
400'
67
500
66
600'
65
800
63
1000'
61
1500
59
2000'
57
dBA
-
FIG. IV-6
DEPRESSED
dBA
dBA (q) 100
(AT- GRADE)
=
70
H
TRUCK
0/0
UP-GRADE
0/0
12
TABLE
IV -3
+
3
73
<3
TABLE
IV-4
+
0
73
TABLE
IV- 4
+
--5-+5
+
YES
ACCELERATION
(INTERSECTION)
PAVEMENT
NORMAL
NO. OF LANES
150'
wide
TABLE
IV-7
2
75
0
75
PSEUDO LANE
LOCATION
48 ft.
from
ledge
HIGHWAY:
ALT.-II
I
L~lii
Y-LINE
FELLS PARKWAY)
: MAINLINE ELEVATED; Y-LINE
AT-GRADE
ul
FIG
-
DESIGN VARIABLES
NO:_6
(QUAD. :
ELEVATION
ATGRADE
DISTANCE
loo,
VOLUME (VPH)
5680
I
SPEED (MPH)
0/0
YES
ACCELERATION
(INTERSECTION)
100'
wide
NO. OF LANES
ALT-II
y
T.TNF
MAP-4)
OUTPUT:
@
IV-2 FIG IV-6
DISTANCE TABLE
AT-GRADE ELEVATED
(ft.)dBA
dBA
100
74
200
70
300
68
400
66
FIG IV-6
DEPRESSED
dBA
100'
(AT- GRADE)
69
F,
TABLE
IV-3
+ 3
TABLE
IV-4
+ 0
TABLE
IV- 4
+
+
NORMAL
PAVEMENT
HIGHWAY:
dBA (
40
<3
see
C,
CORRECTIONS:
TABLJE
IV-1
12
/
UP-GRADE
-
NOISE PREDICTION
FORMAT
INPUT:
TRUCK
VI
('F F . T.-
600
64
800
62
1000
60
1500'
58
2000'
56
N)
0O\
72
74
0
74
40 ft.
f OM
Ieage
P ARK W AY )
: MAINLINE ELEVATED:
65
72
2
PSEUDO LANE
LOCATION
TABLE
IV -7
500'
Y-LINE AT-GRADE
'-U--'
L~I
~-r-
J27
VC
.0y
/(
RESULTANT
NOISE
a u
I
/
B
& C)
CONTOURS FROM
Y-LINE TRAFFIC
(MAINLINE
ALTERNATE-II
v
MAP - 4
QUADRANTS :
MAINL INE
ELEVATED:
Yf-LINEE AT
GRADE)
+
00'
--
I IGO(210)
-
00o (10)
200020t)
I--
775<60)
00(10)
It
Its4
0X
--
ND-----2
-
7L7
aMA
STORAGE
10
,,
\~cO
~
7
PAR
q 14~
IARKA
--
-
MMORO-D
0
1
v
&
128
noise
reduction
(if any)
is not estimated.
Neverthe-
less, we shall keep this point in mind while comparing
the
alternate designs.
MAINLINE AT-GRADE WITH 3 FT. HIGH
SIDE WALLS: Y-LINE ELEVATED
ALTERNATE-III:
Same process
is repeated.
Mainline noise levels
estimated as shown in Noise Format No:
Y-Line the condition is
Format No:
2 and No:
respectively.
7.
are
Since for
similar to ALTERNATE-I, Noise
3 are
used for Quadrants
B and C,
The resultant noise contours for this
alternate are shown in MAP-5.
b.
In the second segment for Quadrant-A*, we shall consider
Here we shall mainly demonstrate the
ALTERNATE-I only.
noise
contour development process for more complex
situations.
In this case there are more than one 'roadway contributing to noise
from Mainline side.
Due to vari-
ations in speeds and other design variables between
Mainline, ramps and local streets,
separately
as
these are considered
following:
Noise Format No:
8 is used for Mainline traffic.
Noise Format No:
9 is used for Mystic Ave N.B. traffic,
and its pseudo lane is assumed at 100 ft.
from the
Mainline pseudo lane.
*Noise Contours for Quadrant 'D'
can be developed using
same process; it is not analysed here.
-
FIG
VI-I --
NOISE PREDICTION
FORMAT
INPUT:
TABLE IV-2
DISTANCE
D0 CAT-GRADE ELEVATED
ELEVATION
AT-GRADE
DISTANCE
100,
VOLUME (VPH)
10,000
NO:
(QUJADS.
TRUCK %
UP-GRADE
PAVEMENT
50
HIGHWAY:
ALT-III
TABLE
IV -3
NONE
@*
3
+ 0
TABLE
IV- 4
+ 0
TABLE
IV-7
:
EPRE9E
dBA
100
76
72
200'
72
68
300'
70.
66
= 73
400
68
64
500'
67
63
600
66
63
800
64
62
1000'
62
60
1500
60
58
2000
58
56
76
76
76
76
PSEUDO LANE
LOCATION
40 ft.
from
edgje
17 -VI
*Corrections
(1-93)
MAINLINE AT-GRADE WITH 3 FT
WALLS: Y-LINE ELEVATED
-- A--
100'
+ 0
8
MAINLINE
+
TABLE
IV-4
NORMAL
NO. OF LANES
dBA (
(AT-GRADE)
<3
ACCELERATION
7
CORRECTIONS:
12
%
(ft.)dBA
: B&C
see"MAP-5)
TABLE
(MPH)
@
FIG IV-6
DESIGN VARIABLES
SPEED
OUTPUT:
HIGH SIDE
TABLE-IV-5
for 3 ft. wall;
ssYST/IC
/(
/
~"
4 ~\MAP
- 5
QUADRANTS :
RESULTANT NOISE
AREA
CO-
ALTERNATE-III
\
Oggw/
it*
.
0AM.
Pu
o
..
n
-L60
AC4= 9e
& C)
CONTOURS FROM MAINLINE
Y-LINE TRAFFIC
(MAINLINE AT-GRADE, WITH 3 FT.
HIGH SIDE WALLS: Y-LINE E]LEVATED)
A
S 4N
-
:
B
131
Ramp
'E',
Ramp
'C'
and
Relocated Mystic Ave.
grouped together and termed as
noise prediction.
N.B.,
'Ramps Configuration' for
Pseudo lane for Ramp Configuration is
assumed at the edge of Relocated Mystic Ave. N.B.
Format No:
are
Noise
10 is used for this group.
It may be pointed out that pseudo lanes for other roadway groups
are assumed at interval
(multiple of 100
ft.)
to
simplify decibel additions.
The
lines parallel to Mainline show the resultant noise
contours for the above three groups of roadways, in MAP-6.
As
showri on the above set, we have superimposed noise
from Middlesex Ave.,
on both sides.
tion
assuming pseudo lanes at roadway edges
Noise Format No:
11 shows noise level estima-
for Middlesex Ave.
The resultant noise
Mainlineside
For
the
are shown
contours
in
Y-Line traffic
estimations,
as
same
for all roadways
from the
MAP-7.
noise, we
conditions
use Noise
Format
No:
apply.
Noise contours from Y-Line side are superimposed over
Mainline noise contours
as shown in MAP-8.
noise contours for all roadways
in MAP-9.
in Quadrant
The resultant
'A'
are
It may be pointed out, that the noise
shown
contour
development process is much simpler on overlays, and on a
scale larger
3.
PHASE
The
C:
than could be presented here conveniently.
Noise
Severity
and
resultant noise contours
Control Analysis
for
studied, and predicted noise levels
each alternate
are
for various land uses
2
-FIG
NOISE PREDICTION
FORMAT
INPUT:
DESIGN VARIABLES
(QUAD.
ELEVATION
AT-GRADE
DISTANCE
100'
VOLUME (VPH)
10,980
(MPH)
UP-GRADE
%
ACCELERATION
PAVEMENT
NO. OF LANES
HIGHWAY:
ALT.-I
50
12
TRUCK %
NO: 8
A, see MAP-6)
CORRECTIONS:
TABLE.
IVSPEED
VI--
<3
NONE
NORMAL
8
dBA
+3
TABLE
IV-4
+0
TABLE
IV- 4
+0
-5--+5
+0
TABLE
IV -7
MAINLINE: (1-93)
MAINLINE AT-GRADE:
PSEUDO LANE
LOCATION
Y-LINE
(D
@
IV-2 FIG. IV-6
DISTANCE TABLE
AT-GRADE ELEVATED
dBA
dBA
100'
76
200
72
300
70
400'
68
500'
67
600
66
800
64
1000
62
1500'
60
2000,
58
@
FIG IV-6
DEPRESSED
dBA
() 100
(AT-GRADE)
TABLE
IV-3
OUTPUT:
ELEVATED
73
76
76
76
76
40 ft.
from
edge
~1~~ .1I
-FIG
NOISE PREDICTION
FORMAT
INPUT:
NO: 9
(QUAD. : A,
DESIGN VARIABLES
ELEVATION
AT-GRADE
DISTANCE
loo,
VOLUME (VPH)
1910
SPEED (MPH)
TRUCK %
%
ACCELERATION
NO. OF LANES
HIGHWAY:
ALT-I
:
@
IV-2 FIG. IV-6
DISTANCE TABLE
AT-GRADE ELEVATED
(ft.)
dBA
dBA
MAP-6)
25
15
TABLE
IV-3
<3%
TABLE
IV-4
(AT-GRADE)
2
+ 4
64
+ 0
64
+ 0
+0
TABLE
IV-7
=60
i
TABLE
IV- 4
NONE
100'
64
200'
60
300
58
400
56
500'
55
600'
54
800
52
1000
50
1500'
48
2000
46
FIG. IV-6
DEPRESSED
dBA
dBA () 100
NORMAL
PAVEMENT
see
OUT PUT:
CORRECTIONS:
TABLE
IV-
UP-GRADE
VI- -
PSEUDO LANE
LOCATION
N§RB
MYSTIC Av.
MAINLINE AT-GRADE; Y-LINE
ELEVATED
64
64
100 ft.
f rom
seudf_Mqe
~~1~~~ 1113-
FIG
-
NOISE PREDICTION
FORMAT
INPUT:
DESIGN VARIABLES
NO:
(QUAD. :,A,
ELEVATION
AT-GRADE
DISTANCE
100'
VOLUME (VPH)
2060
SPEED
VI- -
(MPH)
10
see MAP-6)
CORRECTIONS:
TABLE
dBA (R 100
IV-1
(AT-GRADE)
30
=6 3
OUTPUT:
___
DISTANCE
(ft.)
15
TRUCK %
UP-GRADE
>3
%
ACCELERATION
PAVEMENT
NO. OF LANES
HIGHWAY:
ALT.-I
YES
+ 4
TABLE
IV-4
+
TABLE
IV- 4
+
4
+ 0
NORMAL
3
2
PSEUDO LANE
LOCATION
TABLE
IV-7
RAMPS CONFIGURATION
(RAMP 'E' & RAMP 'C'
: MAINLINE AT-GRADE;
dBA
dBA
100'
73
200'
69
300'
67
400'
65
@
FIG. IV-6
DEPRESSED
dB1A
FH
500'
TABLE
IV-3
@
TABLE IV-2 FIG. IV-6
AT-GRADE ELEVATED
64
I
67
600'
63
800
61
1000,
59
1500
57
2000
55
69
73
73
As sume
se
& REL. MYSTIC AVE.N.B.)
Y-LINE ELEVATED
t1
. I~
- FIG
NOISE PREDICTION
FORMAT
INPUT:
DESIGN VARIABLES
ELEVATION
AT-GRADE
DISTANCE
100.
VOLUME (VPH)
NO: 11
(QUAD. : A, see MAP-6)
CORRECTIONS:
I 1120
SPEED (MPH)
25
TRUCK %
15
UP-GRADE %
VI-I
<3
TRUCKS
ACCELERATION
STOP &
PAVEMENT
DILAPI-
TABLE
IV-
OUTPUT:
(D
DISTANCE
(ft.)
@
E
TABLE IV-2 FIG. IV-6
AT-GRADE ELEVATED
dBA
dBA
100
69
200'
65
300'
63
400
61
500
60
600'
59
800
57
1000,
55
1500'
53
2000
51
FIG. IV-6
DEPRESSED
dBA
dBA () 100'
(AT-GRADE)
TABLE
IV -3
+
TABLE
IV-4
+
TABLE
IV-4
+
SOME
4
0
5
+ 2
=58
62
62
67
69
IDAT TON
TABLE
NO. OF LANES
2
IV -7
PSEUDO LANE
LOCATION *
SUME
II8WAY
V
HIGHWAY:
MIDDLESEX AVE.
ALT.-I*: MAINLINE AT-GRADE:
Y-LINE ELEVATED
I1
f3Uo
*
--
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LENAEI:IMILIEA
-GRADE:
Y-LINE
ELEVATED)
40
are observed.
These are then compared with the respective
'noise goals' as
following:
a.
QUADRANT-B
Land Use-1;
Residential
(medium density)
ALT-I
(MAP-3)
o.W.
C.W.
O.W.
C.W.
O.W.
C.W.
1st two rows:
Mainline side
Pred:* 74-76
NG:**
61-61
Excess:13-15
74-76
69-69
5-7
69-72
61-61
8-11
69-72
69-69
0-3
68-74
61-61
7-13
68-74
69-69
-1 to 5
1st two rows:
Y-Line side
Pred:
NG:
76-78
69-69
7-9
72-74
61-61
11-13
72-74
69-69
3-5
76-78
61-61
15-17
76-78
69-69
7-9
68-74
69-69
-1 to
66-70
61-61
5 5-9
76-78
61-61
Excess:15-17
H
f-I
ALT-III
(MAP-5)
ALT-I I
(MAP-4)
Pred:
two rows:
Mainline & Y-Line sides NG:
Beyond
68-74
61-61
Excess:7-13
68-74
66-70
61-61
69-69
-3 to 1 7-13
68-74
69-69
-1 to 5
Comments :
Note:
The noise excesses should be viewed with reference to
-Table VI-1 in the following discussions:
i)
*Pred.
**NG. --
--
For uses beyond lst rows of houses,
Predicted
Noise Goals
(dBA)
(dBA)
the attenuation effects of
intervening buildings
levels,
(if any)
are not reflected in the predicted noise
due to absence of such general guides.
However, cross-section
for line of sight analysis as shown in Fig.-VII-2 and Fig.-VII-3 would
enable us to make some qualitative judgments.
ii)
The above
first two rows
houses --
comparison indicates ALT-II being less noisier..
on Mainline side are in
69 dBA),
with open windows;
'marginal range'
The
(about 2/3
elevation has offered some relief.
On Y-Line side noise is reduced due to elimination of acceleration and
grades; however, noise levels
may be
recommended.
are in onset of noise problem range;
Beyond lst two row, noise
environment is
walls
in marginal
range.
iii)
case.
With closed windows noise levels would be
For ALT-II this brings down the noise to
iv)
reduction
8 dBA lower in each
'negligible' range.
It is observed that elevated roadway section provides noise
(e.g., ALT-II, Mainline); but elevation achieved in the immediate
vicinity results
acceleration
in higher noise level due to introduction of grades and
(e.g., Y-Line ALT-I).
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v)
Noise environment for houses behond two rows may be better than
indicated by noise contours, due to intervening buildings;
houses on far side of hill
(beyond 900 ft.,
may provide some shielding effect.
Land Use-3;
The topography
These items require further research.
School
ALT-I
(MAP-3)
0.W.
H
Fig. VII-2).
also for
Classrooms
Auditorium
ALT-II
(MAP-4)
ALT-III
(MAP-5)
C.W.
O.W.
C.W.
O.W.
C.W.
Pred:
70
NG:
50
Excess:20
70
58
12
68
50
68
58
67
50
67
58
18
10
17
9
Pred:
70
45
NG:
Excess:25
70
53
17
68
45
68
53
15
67
45
67
53
14
23
22
Comments:
i)
ALT-I;
ALTERNATES II
and III are about equal, and slightly better than
however it may not be noticeable.
But considering the improvements
for residential uses, ALT-II
ii)
Classrooms
--
is preferredfor Quadrant-B on overall basis.
with open windows protest expected, the situation
requires better insulation and air conditioning provisions
(to keep
windows closed).
iii)
Auditorium
protest expected;
iv)
--
probably closed windows condition applies;
special insulation required.
The intervening buildings would probably cause some attenuation
(see Fig. VI.I-3).
The actual attenuation
detailed acoustic analysis, including
the effect of existing
Hi
still
determination would require
field measurements, to establish
intervening buildings.
Such analysis could be
recommended as
a part of preliminary highway design investigation
soil borings),
ard would clarify the need for insulation measures and
(like
cost.
For school the noise levels due to expressway traffic would be
high, and protest is expected.
Special
insulation. ireasures are recom-
mended.
'11MINIM
I I III I
MENNOWNmo-
b.
QUADRANT-C
Land Use-1;
Residential
(medium density)
0.W.
ALT-III
ALT-II
(MAP-4)
ALT-I
(MAP-3)
(MAP-5)
0.W.
C.W.
C.W.
0.W.
C.W.
1st two rows
Y-Line side
70-72
Pred:
61-61
NG:
Excess: 9-11
70-72
69-69
1-3
66-70
61-61
5-9
68-70
66-70
61-61
69-69
-3 to' 1 7-9
68-70
69-69
-l to 1
Beyond two rows
Mainline & Y-Line side
66-70
Pred:
61-61
NG:
Excess: 5-9
66-70
69-69
-3 to
65-69
61-61
1 4-8
65-69
61-61
0 4-8
65-69
69-69
-4 to 0
65--69
69-69
-4 to
Comments:
i)
Houses in this residential use are not directly exposed to
Mainline traffic;
on the Y-Line side presence of "Foss Park" might ha.ve
some psychological effects.
ii)
ALT-II has
lower noise
levels
on the whole;
'marginal' range, and with closed windows
with open windows
ignored range, noise predicted.
The above mentioned factors might further lower the noise effects
Land Use-2;
Residential
(high density)
ALT-I
(MAP-3)
O.W.
C.W.
ALT-II
(MAP-4)
0.W.
1st two rows
Mainline side
Pred:
NG:
Excess:
70-74
70-74
68,
65-65
73-73
65
3
5-9
-3 to 1
Beyond two rows:
Mainline side
Pred:
NG:
Excess:
66-70
66-70
65-65
73-73
1-5
-7 to-3
ALT-III
(MAP-5)
C.W.
0.W.
68
73
-5-
67-70
67-70
65-65
73-73
2-5
-6 to -3
65-68
65-68
65-65
73-73
0-3
-8 to-5
C.W.
64-67
64-67
65-65
73-73
-l to2 -9 to-6
Comments:
i)
ALTERNATES II
for 1st two rows,
lst two rows.
and III are similar; however ALT-II seems better
wh.ile ALT-III is slightly less noisier for areas beyond
This
is because in that range Walls are still effective,
while Elevation begins getting ineffective.
ii)
For ALT-II, even with open windows dBA is in
and probably will be ignored in the project housing.
'ignored' range,
Land Use-4;
Note:
For
Church:
'Rectory' part of church
'Use-i; Residential' would apply;
for Church proper the noise contours
apply, and Sunday morning
Rectory
Mainline
side
for design hourly traffic do not
(10 A.M. to 12 Noon) traffic will be considered.
Pred:
NG:
Excess:
ALT-I
(MAP-3)
ALT-II
(MAP-4)
ALT-III
(MAP-5)
o.W.
C.W.
O.W.
C.W.
O.W.
C.W.
71
61
10
71
.69
2
68
61
7
68
69
-l
68
61
7
68
69
-1
Comments:
i)
ALTERNATES II and III have equal noise, hence overall effects
be considered.
ii)
ALT-JI favored.
ALT-II, open windows condition, is in marginal range.
is directly exposed to Mainline traffic.
Rectory
Acoustic barriers and buffers
may be considered to eliminate the direct exposure, and provide psychological effects.
-
NO:
(QUAD.
DESIGN VARIABLES
ELEVATION
AT-GRADE
DISTANCE
100
SUNDAY- ioAM TO 112.
12
:
C)
OUTPUT:
(D
CORRECTIONS:
@
IV-2 FIG. IV-6
DISTANCE TABLE
AT-GRADE
ELEVATED
dBA
dBA
l00
FIG. IV-6
DEPRESSED
dBA
74
200
00*-
300'
VOLUME (VPH) 15425
TABLE
IV-1
n
VI-I
NOISE PREDICTION
FORMAT
INPUT:
0
FIG
d B A (a) 100'
(AT-GRADE)
= 71
SPEED (MPH)
50
TRUCK %
12
TABLE
IV-3
+
<3
TABLE
IV-4
+ 0
TABLE
IV- 4
0
74
-5--+5
O
74
400'
66
500
UP-GRADE
%
ACCELERATION
NONE
PAVEMENT
NORMAL
NO. OF LANES
HIGHWAY:
ALT-I _:
8
TABLE
IV-7
CHURCH AT 400 FT.
IMAINLINE AT-GRADE;
3
74
600'
74
800
PSEUDO LANE
LOCATION
40 ft.
from
edge
FROM MAINLINE
(1-93)
Y-LINE ELEVATED
1000
1500
2000'
-nT:11P,4
- FIG VH-INOISE PREDICTION
FORMAT
INPUT:
DISTANCE TABLE IV-2 FIG. IV-6
AT-GRADE ELEVATED
DESIGN VARIABLES
ELEVATION
AT-GRADE
DISTANCE
100,
non
VOLUME (VPH)
2841
SPEED
(MPH)
100'
CORRECTIONS:
dBA
.Edg
FIG IV-6
DEPRESSED
dBA
76
200'
300'
dBA (6® 100
(AT-GRADE)
40
TRUCK %
00t
NO: 13
(QUAD.
C)
TABLE
IV-1
Hi
n
OUTPUT:
12
TABLE
IV3
>3
400
= 67
500
70
+ 3
=
TABLE
IV-4
+ 2
= 72
TABLE
IV- 4
+ 4
600
UP-GRADE %
ACCELERATION
PAVEMENT
NO. OF LANES
HIGHWAY:
ALT.-I
YES
800
1000
TABLE
IV-7
wd ft
wide
Air
76
+ 0
NORMAL
PUTI
=76
1
MAINLINE
rr
PSEUDO LANE
LOCATION
VPCM
AT-GRADE;
V-T.TWR
Y-LINE
1500
40 ft.
from
edge
(F-T.T.5q
ELEVATED
PARKWAVI
60
2000
17 --I-
I
Church:
Considering Sunday morning
(10 A.M. to 12 Noon) traffic, we estimate
the noise levels as following:
-
Location:
400 ft. from Mainline, and 1500 ft.
-
Mainline:
Hourly Traffic Volume for Sunday morning
Condition
from Y-Line
(ADT) .
5% of Average Daily Traffic
0.05 x 108,500 = 5425 Vechicles per hour
-
As shown in Noise Format No:
get dBA at 400 ft. = 66 dBA
Format No:
H
-
12,
using this traffic volume we
(this is
2 dBA below dBA,
Similarly Y-Line Hourly Traffic Volume =
Using
this
Format No:
-
0.05 x 56820
2841 VPH
traffic volumewe get dBA at. 1500 =
60
dBA
(see Noise
13)
Resultant dBA =
higher
in Noise
1 for the same distance)
=
-
(VPH)
value =
66-60,
66
+
1
difference =
67 dBA
6,
therefor add 1 to
the
(Table IV-8)
By similar calculations we get following noise levels for the three
alternates:
ALT-I
Church:
ALT-II
ALT-II
O.W.
C.W.
66
64
64
53
45
53
13
19
11
O.W.
C.W.
O.W.
C.W.
Pred:
67
67
66
NG:
45
53
45
Excess:
22
14
21
Comments:
i)
ii)
Closed windows condition would apply.
Church is directly exposed to Mainline traffic
Alternates.
for all the three.
ALT-III is relatively slightly better, but the difference
may not be noticed
(beyond 400
ft. Elevation attenuation ineffective,
while Wall attenuation diminished).
L4)
iii)
Noise
levels
indicate
'onset of
serious
better insulation provisions are warranted.
noise
problem,'
thus
Also acoustic barriers and
buffers recommended to eliminate the direct exposure, and provide psychological effects.
Land Use-5;
Commercial:
ALT-I
(MAP-3)
0.W.
Pred:
70-76
NG:
55-55
Excess:15-21
ALT-II
(MAP-4)
- ALT-III
(MAP -5)
C.W.
O.W.
C.W.
O.W.
70-76
63-63
7-13
69-71
55-55
14-16
69-71
63-63
6-8
68-73
55-55
13-18
C.W.
.68-73
63-63
5-10
Comments:
i)
ii)
H
Generally ALT-II seems
in relatively lower noise range.
Closed windows condition would apply, and for ALT-II noise
excess might be ignored.
Land Use-7;
Some insulation measures be considered.
Park:
ALT-I
(MAP-3)
ALT-II
(MAP-4)
Pred:
Background Noise:
70-78
59-59
66-76
59-59
70-78
59-59
Excess:
11-19
7-17
11-19
ALT-III
(MAP-5)
Comments:
i)
Please refer to discussion under Phase-A, Establishment of Noise
Goals for Park.
ii)
ALT-II is
less noisier;
due to active sports the noise excess
might be ignored.
C,
QUADRANT-A
(Note:
Only ALT-I analysed;
Land Use-6;
please refer to MAP-9)
Light Industry
H
O.W.
Triangular area between
Mainline, Y-Line and Middlesex Ave.
Pred:
72-80
NG:
.60-60
Excess:12-20
C.W.
72-80
68-68
4-12
Comments:
i)
Closed windows condition would apply;marginal range.
Better insulation would improve
conditions.
ii)
Elevating Mainline
(ALT-II) would result in some
improvement
though Ramps would be still generating high noise levels.
Beyond Middlesex Ave:
Within 200 ft.
Pred:
NG:
Excess:
Beyond 200 ft.
Pred:
NG:
Excess:
0.W.
C.W.
72-78
60-60
12-18
72-78
68-68
4-10
66-72
60-60
6-12
66-72
68-68
-2 to 4
Comments:
i)
Closed windows
condition would apply.
Noise excess will be
probably ignored due to already heavy truck traffic.
Land Use-8;
Court:
Pred:
NG:
Excess:
0.W.
C.W.
79
46
33
79
54
25
Comments:
i)
ii)
Closed windows condition would apply.
Although the existing background noise level is 5 dBA higher than
the specified noise goal,
the excess noise due to new expressway traffic
indicates serious noise problem.
recommended.
somewhat
Elevating Mainline
Special insulation provisions are
(ALT-II) would improve overall conditions
(also acceleration and grades will be eliminated on Y-Line).
158
d.
Conclusions for Case
Through the
Study Alternates
foregoing analysis we have demon-
strated the application of noise prediction guides
and have laid a framework in which alternate
highway designs
their noise
could be
compared in terms of
severity on various land uses
highway corridor.
The above
ALTERNATE II to be
relatively
in the
comparison indicates
However
less noisy.
for the overall evaluation this has to be
viewed
in the context of tradeoffs and conflicts with
other goals variables
study we
scope of this
of various actors.
In the
do not have information or
situational data to undertake such tradeoff
However, following
analyses.
'guesses' are made
to indicate the kinds of tradeoffs
involved.
Community disruption and highway as a barrier in
the community:
be defined.
be
For this purpose
community has to
School district and church parish to
investigated.
By establishing such linkages,
pattern and extent of travel between Quadrants B
and C
(and also other adjoining areas) could be
studied.
If it is
actually observed that many
persons from Quadrant B go to church in the
Quadrant C,
and students
school in Quadrant B,
from Quadrant C attend
then ALTERNATE II would be
least disruptive, by allowing travel through
159
Shore
Drive
and
Temple
and III, would cut
Road, while ALTERNATES
off such linkages.
by providing over and underpasses,
travel could be
restored.
a heavy traffic artery,
I
However,
pedestrian
(It may be added, that
i.e.,
Mystic Avenue,
is
already passing through the two quadrants.)
Aesthetic:
For aesthetic and cost purposes, two
versions of ALTERNATE
II
could be considered:
One, Mainline elevated on embankment fill with
retaining walls;
the
viaduct structure.
other, Mainline elevated on
Mainline on fill will pose
as a visual obstruction and
dividing wall.
The
viaduct structure,
if designed carelessly to merely
support
could look like a steel and
the loads,
concrete jungle.
However, with due
considerations,
sleek viaduct structure could allow visual
interaction
as weal as park and playground
under the roadway.
cal effects
space
Better visual and psychologi-
could be achieved by landscaping of
these areas.
The heavy moving traffic on Mainline at grade
scheme
(ALTERNATES
I
and
present an unpleasant
to high noise
Cost:
and
fume
III)
,
probably
would
and hectic view, in addition
levels.
On relative basis,
Mainline elevated scheme
would cost more than at grade scheme
due to cost
of
160
Mainline on embankment fill
viaduct structures.
with retaining walls would be cheaper than Mainline
However, in this area due to adverse
on viaduct.
soil conditions
'retaining walls' will have to be
supported throughout on pile foundations, and pose
Comparing the two versions of
difficult problems.
Mainline at-grade
schemes, the difference is be-
tween the cost of Steel Beam Highway Guard for
ALTERNATE-I
(at $5.30 per
foot)
(7)
and 3 ft. high
solid side walls for ALTERNATE-III
per foot).
(8)
The
3 ft.
(at about $15.00
side wall, however, when
designed as recently proposed General Motors Barrier,
(9) will have additional Safety features.
Such barrier is being proposed on the interstate
projects.
Effects on Traffic Movements:
I & III,
ALTERNATES
would not allow left hand traffic turn from Relocated
Mystic Av. N.B. to McGrath Highway.
In order to
allow this turn the Mainline will have to be
over Temple Road, and the Bailey Road
street) will have
raised
(a local
to accommodate this move, and
by conversion to one way street.
Furthermore,
for ALTERNATES
I & III,
Line-'F'
(left turn move from Fells Parkway to 1-93
S.B.)
is considered on a third level, where as for
ALTERNATE-II this move
ALTERNATE-II will be
less
is accommodated in tunnel.
noisy,
as well
as the
161
dominating effects
of a third level structure will
be avoided.
These are, then, some of the trade-offs to be
investigated.
Situational data base and prediction
techniques for other goal variables are needed to
undertake such analyses.
This brings
to close the
comparison of three
alternates in terms of their noise severity and
some
comments on the trade-offs.
In the next
chapter overall conclusions would be drawn from
the
theoretical analysis
Case Study.
(Part One),
and the
CHAPTER-VIII
Conclusions
This research was undertaken when the author was
working
as a
'Research Assistant' on
the
N.C.H.R.P. Project,
'The Impacts of Highways Upon Environmental Values.
(1)
In response to the felt need for prediction techniques,
through which highway designers could relate the
impacts
of alternate designs to the environmental goals of impacted actors, in this study prediction
one of the environmental values were
is noise effects
from highways.
techniques for but
investigated.
That
However, noise prediction
techniques were viewed in the framework of a broader
highway desiqn process, in which the ultimate qoal is better
control over the environmental impacts of highways.
In the noise contour development process
and its
application to the Case-Study a framework of analysis has
been laid down,
could be
through which alternate highway designs
compared in terms of their noise
trol measures could be recommended.
perhaps more objective in
terms at present.
effects, and con-
Such comparison is
'relative' terms than in- 'absolute'
But as more knowledge and techniques be-
come available for predicting people's reaction to noise
levels,
and attenuation effects
of intervening buildings,
and topography, the objectivity of noise prediction techniques is anticipated to increase.
162
163
Almost all the relationships between highway design
variables and noise levels used in the development of noise
contours had been established by the Bolt Beranek and Newman
Inc.,
in their noise studies over the years, particularly
in their Report No:
1505
(2)
this research is primarily
knowledge.
As such the contributions of
.
to my own understanding and
When the study was begun, I did not know the
definition of
'dBA;'
at the
completion of
'Case-Study,'
I
have been sensitized to the noise impacts of highway design
variables, and can undertake comparison of alternate highway desings at least
in relative terms.
It is hoped that
other highway engineers could also benefit
from the Case
Study presented, and could exercise better control over
the noise
levels of their generated designs.
Following comments and recommendations are proposed
from the various parts of this
Study:
The value of a noise measure which could be recorded
directly and conveniently in field
(in addition to its high
correlation with human judgment) became
Case Study.
apparent in the
In many places along the highway
corridor
there will be a need to measure the existing noise levels
to evaluate the existing noise environment and gain insight
into effects of topography and intervening structures.
as a measure of vehicle noise is
The
thus of substantial value.
objectivity of noise levels relationships with
highway design variables have been well established by
simulation
dBA
studies of BBN. (3)
However, the statistical
164
distributions for noise levels in Table-IV-1 were not presented here.
For example,
percent trucks, at distance
for 10,000 vph, with 5 to 10
of 200 to 500 ft.,
Deviation of 2.3 has been reported.
(4)
a Standard
The Standard
Deviation is further diminished with increase in traffic
volume and distance, and decrease in truck volume.
order to
In
simplify calculations and noise contours plotting,
we have used dBA in terms of single number, with the assumption that 2 to 3 dBA Standard Deviation shouldn't prove
crucial.
The attenuation effects of intervening buildings
and topography requires extensive research.
ficult
It may be dif-
(and perhaps not feasible) to give one general state-
ment for all geometric configurations due to large number
of the variable involved.
But perhaps as a result of ex-
tensive and systematic line of sight analyses and field
measurements, ranges of attenuation might be recommended.
The prediction of noise
levels from the highway
design variables as synthesized in the Noise Prediction
Format
(Fig. VI-l),
could be incorporated into a computer
program.
The logic is
simple,
steps are
involved.
stored as
library or subroutines.
The
and additions/subtraction
'correction tables'
could be
In fact, BBN has devel-
oped a computer based simulation model which plots
'histograms', showing statistical distribution of noise
levels over time, at a particular distance, using traffic
volume,
speed, and truck percent as inputs. (5)
The
165
simulation histograms have exhibited close correlation with
the actual field measurements.
Such a model could be fur-
ther expanded to incorporate grade, elevation and other
However, we have taken somewhat different ap-
variables.
proach in this
study.
Instead of developing detailed
'histograms' for one particular point in the highway
corridor
(which may be required in many cases),
we have
attempted to develop noise contours for the entire highway
corridor, to study the noise effects simultaneously for all
land uses.
And it is
felt that the steps presented in
Noise Prediction Format are so simple and straightforward
that perhaps
program.
prefer
grams
the purpose is served, without a computer
Many highway engineers
and agencies would probably
'tables and charts' to sophisticated computer proOn the other hand where
(unless they are warranted).
a large number of design alternates
are involved, plotting
noise contours and dBA additions at the grid intersection
(in particular) ,could prove time consuming mechanical
steps.
A computer model that could
levels from highway design variables
first estimate noise
(using the logic
presented in the Noise Prediction Format),
on a base map at 100 ft. intervals,
then plot dBA's
super impose dBA's
from crossroads and add dBA at grid intersections
probably could be accomplished in
(this
'computer's mind',
without
actual plotting, by establishing a coordinate system),
to
develop the resultant noise contours, may be probably
worthwhile
to investigate.
It may be added, however, that
166
development of noise contours on overlays is a much simpler
process than could be presented within the constraints of
the
'Thesis' requirements and scale.
It may be also pointed
out that most of the data needed to develop the noise contours are generally available to a highway engineer, engaged in the development of highway design alternates
(e.g.,
traffic volume,
speed, percent trucks, grades,
etc.).
It is therefore anticipated that development of noise con(like drainage contours) could
tours as a routine procedure
be operationalized almost instantly
(with the necessary
training of highway engineers, of course).
While prediction of noise levels from the highway design
variables have been established with reasonable degree of
accuracy, predicting people's reactions to noise levels is
a much more complex problem.
noise
We do not have
'acceptable
levels' that could be applied objectively to everyplace
and everyone.
Multivariate
analysis techniques are urgently
needed to infer people's reactions
pontext of total environment.
to noise
levels in the.
Such techniques could be
designed to be valuable for a broader highway design process
in which peopie's values for a large set of goal variables
could be obtained simultaneously.
The noise
contours for the alternates in the Case
Study indicate that generally uses
1st 200 ft.
high noise
have
approximately in the
range from the roadway edge are subjected to
levels. Even if the
front row buildings might
some attenuation effects for uses behind them, these
167
buildings bear the brunt of noise severity.
Sensitivity to
the noise effects on the residents of these buildings
urgent.
is
Insulation provision for these buildings could be
logically recommended as part of a highway construction.
Location of
activities could be based in the
framework of
compatible noise levels along the highway corridor.
In
addition, highway design variables could be manipulated
in relation to land uses and their noise sensitivity.
However, in the manipulation of design variables the conflicts
and tradeoffs with other goal variables should be
recognized.
For example, a roadway section may be depressed
to reduce noise severity on adjoining residences;
such a
measure would obstruct driver's view of the adjoining areas,
and may
also prevent significant features of the adjoining
community
(which the community might like to display) from
being seen.
Therefore, this depressed section should be
designed in the
context of the total design of roadway as
a linear system, in which depressions could provide dramatic
effects for the immediately following vistas. (6)
Furthermore., the inspection of noise contours for the
three
alternates
(MAPS 3, 4 and 5) indicate that noise re-
ductions as a result of changes in design variables are
also mostly effective
from the roadway edge.
in approximately lst 200 ft.
range
Following comments may summarize
the effective range of some of the design variables
168
-
Elevation
400 ft.
it
is primarily effective
is ineffective.
for lst rows; beyond
Residential uses along the
Mainline have benefitted from elevation, while improvement
in the
ft.,
school noise levels would be unnoticed.
Walls are also primarily effective
for the 1st 500
though there is 2 dBA reduction beyond 500 ft.
-
Depressed condition was not studied;
Fig. VI-6, it's effective
but from
range is evident further out
than elevated condition.
-
In addition, though elevated sections provide acoustic.
shielding, elevation achieved in the immediate vicinity
could deteriorate the situation, due to introduction of
grades and .acceleration.
noise
This is evident by comparing
contours along Y-Line
ALTERNATE-II
(MAP-4).
noise levels are
for ALTERNATE-I
(MAP-3) and
In ALT-II, where Y-Line is at grade,
lower than ALT-I where Y-Line is elevated.
This is due to elimination of grade and acceleration in
ALT-II.
The highway engineer should be aware of the noise
variations due to such variations in the design variables.
-
Ramp grades should be also cautiously designed.
past the tendency has been to design shortest ramp
lowest cost),
(with
and consequently steepest allowable grades.
For noise control, ramps with flatter grades
times
In
at higher costs) could be recommended.
(even someAlso, the
location of ramps could be viewed in terms of noise sensitive areas.
169
-
A
fresh look at policies regarding speed-curvature
control is recommended.
The current Interstate Design
Standards may be modified to allow lower speeds in the
noise sensitive section.
over truck
Also, control can be exercised
routes and traffic volumes to improve noise
environment, when warranted.
cised in the
Such controls would be exer-
context of overall transportation planning.
It is anticipated that the noise contours along the
highway corridor would clarify and specify the need and
location for noise improvement measures,
in addition to
serving as a framework for highway location design and
land use planning in the highway corridor.
170
CHAPTER-I,
REFERENCES AND NOTES:
1.
Committee on the Problem of Noise, "Noise: Final Report
to the Parliament by the Lord President of
Presented
the Council and Minister for Science by Command of Her
Majesty," London, Her Majesty's Stationary Office,
July, 1963, p.22; actually there were 540 observation
points equally .spaced over 36 square miles of Central
The 84% estimation is based on the completed
London.
analyses of about 400 points.
2.
Greater London Council, "Traffic Noise" London, Greater
London Council, February 1966, p. 4 .
3.
Bolt Beranek and Newman Inc., "Noise in Urban and
Suburban Areas: Results of Field Studies, " January 1967.
4.
Bolt Beranek and Newman Inc., Report No: 1505 "Urban
Highway Noise -- Measurement Simulation and Mixed
Reaction".
5.
Bolt Beranek and Newman
No: 1594.
6.
Highway Research Board," Joint Development and Multiple
Use of Transportation Rights-of-Way," Special Report 104.
Proceedings of a Conference Held November 14-15, 1968,
Washington, D.C.
Inc.,
Mimeographed Report
171
CHAPTER II,
REFERENCES AND NOTES:
1.
Manheim, Marvin L., Proposal for National Co-operative
Highway Research Program, Project 8-8, "The Impacts of
Highways Upon Environmental Values," M.I.T. Urban
Systems Laboratory, April 1968.
2.
Banerjee, Tridib, Memorandum to NCHRP Project Participants (at M.I.T.), December 9, 1968. (Unpublished)
3.
Hill, Morris, "A Method for the Evaluation of Transporation Plans," Highway Research Board, Record - 180,
Washington, D.C., 1967; our presentation of design
viariables-goal variables relationship through prediction
model, resembles the Transportation Goal Flow Chart,
Fig.-l, p.27.
4.
Manheim, Marvin L., "Problem Solving Processes in
Planning and Design" Professional Paper P 67-3, Department of Civil Engineering, M.I.T., Cambridge, Massachusetts, January 1967.
5.
Ibid, p.15-a.
6.
American Association of State Highway Officials, "Road
User' s Benefit Analysis for Highway Improvements,"
Washington, D.C. AASHO, 1960.
7.
deNeufville, Richard L., "Towards a Comprehensive
Systems Analysis for Transportation Planning:
An
Urban Example,"
Professional Paper P 67-7, Department
of Civil Engineering, M.I.T., Cambridge, Massachusetts,
June 1967, p.l.
8.
McHarg, Ian L., "A Comprehensive Highway Route Selection
Method", Highway Research Board, Record - 246, Washington,
D.C., 1968, p.l.
9.
Barton-Aschman Associates, "Joint Project Concept-Integrated Transportation Corridors," Chicago, Illinois,
1968.
10.
Highway Research Board, "Joint Development and Multiple
Use of Transportation Rights-of-Way", op. cit.
11.
Woods, Kenneth B., "Highway Engineering Hand Book,"
New York, McGraw Hill, 1960.
12.
American Association of State Highway Official,"A
Policy on Geometric Design of Rural Highways" Washington,
D.C., 1965.
172
13.
Highway Research Board, "Highway Capacity Manual,"
Washington, D.C., 1965'.
14.
Wohl, Martin and Brian, V. Martin, "Traffic System
Analysis for Engineers and Planners," New York,
McGraw Hill, 1967.
15.
Martin, V.V., Memmott, F.W., and Bone, A.J., "Principles
and Techniques of Predicting Future Demand for Urban
Area Transportation, M.I.T. Report - No:3, M.I.T. Press,
Cambridge, Massachusetts.
16.
Efforts of Highway Research Board in cooperation with
the American Association of State Highway Officials
are directed towards research and development in these
areas.
17.
AASHO,
18..
McHarg, op.
19.
Barton-Aschman Associates,
Aspects", pp. 90-104.
20.
Woods, Kenneth B., op. cit.,
of Right-of-Way" p. 6-9.
21.
deNeufville,
cit.,
Participants,
22.
op.
"Road User's Benefit Analysis,"
cit.
p.2.
op. cit.,
Section-6,
Memorandum
Richard L.,
Chapter-5,
to
"Acquisition
NCHRP
1969.
February 4,
(at M.I.T.)
"Legal
Project
(Unpublished).
M.I.T. Urban System Laboratory, Report No. USL-69-l,
NCHRP Final Report - Phase-1, Study Design "The Impacts
of Highways Upon Environmental Values
Massachusetts, March 1969, p. 134.
p.
,
Cambridge,
29.
23.
Hill, Morris, op.
24.
Ellis, Raymond H. and Worral, Richard D., "Towards
The Utilization of
Measurement of Community Impact:
Longitudinal Travel Data to Define Residential Linkages, "
Highway Research Board, Record - 277, 1969, pp. 25-39.
25.
deNeufville, Richard L.,
op. cit.
26.
Hill,
27.
deNeufville,
op. cit.
Richard L.,
28.
AASHO,
User's
Morris, op.
"Road
cit.,
"
cit. p.
Professional Paper P 67-7,
21.
Professional Paper P 67-7,
Benefit Analysis,"
op.
cit.
173
29.
M.I.T. Urban System Laboratory, "Impacts of Highways
Upon Environmental Values", op. cit.; the desired
characteristics of an 'Evaluation Meth'od' are discussed in detail in this reference.
30.
Professor Frank C. Colcord, Jr., Assistant Professor,
Political Science, M.I.T., made a presentation before
the N.C.H.R.P. project participants (at M.I.T.), based
upon his observations and visits to major cities in
the U.S. to investigate the -variations in environmental
values at difference places.
31.
Morehouse, Thomas A., "The 1962 Highway Act:
A Study
in Artful Interpretation," Journal of the American
Institute of Planners, May 1969, pp. 160-168.
32.
M.I.T. Urban System Laboratory,"
of Highways," op. cit., p. 134.
33.
Ibid. p.1
38
.
Environmental Impacts
174
CHAPTER-III, REFERENCES
op.
cit.,
p.
2
.
Committee
2.
Finch, D.M., "Motor Vehicle Noise Studies, Highway
Research Board, Bulletin-105, Washington, D.C.,
p.
2 4
the Problem
of Noise,
1.
1955,
on
AND NOTES:
.
3.
Peterson, Arnold P.G. and Gross, Ervin E., Jr.,
"Hand Book of Noise Measurement," General Radio
Company, West Concord, Mass., 1967, p. 1 1 .
4.
Ibid.,
p.
5.
Ibid.,
pp. 8-10.
6.
Bolt Beranek and Newman Inc., Report No. 1196,
"Selection of a Unit for Specification of Motor
p. 6 .
Vehicle Noise," February 1965,
7.
For an interesting explanation
response mechanism see, Finch,
8.
For detailed explanation of Noise Level Meters and
Noise Measuring Instruments see,"Hand Book of Noise
Measurement", op. cit.
9.
Committee
on
10.
BBN
Report No.
11.
Research
BBN Inc., Report No. 1195, "Interim Report -of Establishment of Standards for Highway Noise Levels,"
Inc.,
11
.
the
February 1965, p.
Problem of
9
1505,
of the human ear's
D.M.,op. cit., p.26.
Noise, op.
cit.
op. ,cit., p.13.
.
12.
For example see, 'Procedures for Calculating Loudness,'
Handbook of Noise Measurement, op. cit., p. 4 9.
13.
BBN
14.
Stevens, S.S., "Procedure for Calculating
Mark VI," Journal of the Acoustic Society
Vol.
15.
Inc.,
Report
33, No.
Zwicker,
E.,
11,
1196,
cit.,
p.
November 1961, pp.
"Ein Verfahrer Zur
Acustica, Vol. 10, No.
16.
op.
1,
6
.
1577-1585.
Berching
1960, pp.
Loudness:
of America,
der Lautstark,"
304-308.
For detailed explanation and comparison of these two
systems please see "Hand Book of Noise Measurement,"
op.
cit.,
pp. 49-52.
175
Book
of Noise
Measurement, op.
cit.,
p.
47.
17.
Hand
18.
Kryter, K.D., and Pearson, K.S., "Some Effects of
Spectral Content and Duration on Perceived Noise
Level," Journal of the Acoustical Society of America,
Vol. 35, No. 6, June 1963, pp. 866-883.
19.
Beranek,
1954, p.
L.L.,
41 9
"Acoustics" New
York,
McGraw
.
of
Noise Measurement,
op.
cit.,
p.57.
20.
Hand Book
21.
Greater London
22.
BBN
23.
For details of these two experiments please
Inc., Report No. 1196, op. cit.
24.
The Wilson Committee (Committee on the
Noise, op. cit.), also employed dBA in
noise study.
Inc.,
Hill,
Council,
Report No.
Traffic
1195,
op.
Noise, op.
cit.,
p.4.
cit.
see,
BBN
Problem of
their vehicle
176
CHAPTER IV,
/
Beranek &
REFERENCES AND
1505,
Report
Newman Inc.
1.
Bolt
2.
Bolt Beranek & Newman Inc., Noise
Suburban Areas, op. cit., p. 11.
3.
Bolt
Beranek
NOTES
in
No.
Report
& Newman Inc.
cit.,
op.
Urban
p.16.
and
cit.,
op.
1594,
Table-6.
4.
Beranek
Bolt
Fig.-2,
5.
Beranek
Bolt
p. 1
3
& Newman
Inc.,
Report
1505,
op.
cit.,
Inc.,
Report
1594,
op.
cit.,
& Fig.-3.
& Newman
.
Table-9.
6.
Ibid,
7.
BBN Report
8.
Ibid, p.24.
9.
Ibid, p.19.
1505,
op.
cit.,
p-B-19.
op.
cit.,
Footnotes
10.
BBN
Report 1594,
11.
BB
Report 1505,op.
12.
BBN
"Noise
13.
BBN Report 1594,
14.
Weiner, E.M.,
in Urban
cit.,
and
p.18.
Suburban
op. cit.,
of Table-6.
op.
Areas,"
"Sound Propagation Outdoors,"
Rettinger, M.
"Noise Level
Noise Control, Vol.
16.
Ibid.
17.
Weiner,
p.
18.
E.M. ,
3, No.
p.13.
p.16.
L.L. Beranek, ed., McGraw-Hill
Reduction.
1 9 2
.
Inc., New York, 1960, Chapter 9, p.
15.
cit.,
Reduction
5,
of
Noise
Book
Co.,
Barriers,"
1957, p.50.
"Sound Propagation Outdoor",
op.
cit.,
193.
Hirtle, P.H., Watters, B.G., and Cavanaugh, W.J.,
Some Case Histories",
"Acoustic of Open Plan Spaces --paper presented at the 77th meeting of the Acoustical
Society of America, April 1969, FIG.9.
177
19.
Rettinger,
op.
cit.,
M.
p.
E.M.,
"Noise Level
Reduction of Barriers"
51.
20.
Weiner,
21.
Hand
22.
Thiessen, G.J.,
"Survey of the Traffic Noise
abstract, Journal of the Acoustic Society of
Vol. 37, No. 6, New York, June 1965.
23.
Rettinger,
Freeways,"
Book
"Sound Propagation Outdoors"
of Noise
Measurement
-
1967,
op.
cit.
op.cit. p.
4
4.
Problem,"
America,
M., "Noise Level Reduction of Depressed
Noise Control, Volume 5, No. 4, 1959, p.
1 4
.
24.
Cohen, A.,
"Location--Design Control of Transportation
Noise," Journal of the Urban Planning and Development
Division Proceedings of the American Society of Civil
Engineers. December 1967, p. 7 8 .
25.
Weiner,
E.M.,
"Sound Propagaticn
Outdoors,"
op.
cit.,
p.194.
26.
BBN
1594,
op.
cit.,
Table-13.
27.
BBN Report 1505,
op.
cit.,
p.47.
28.
Wiener, F.M., Malme, C.I., and Gagos, C.M., "Sound
Propagation in Urban Areas" Journal of the Acoustical
Society of America, Vol. 37, pp. 738-747, April 1965.
29.
Bolt Beranek and Newman Inc., "Noise in
Suburban Areas," op. cit., p.9.
30.
Ibid.
31.
BBN Report
32.
Miller, L.N., "Case Histories of Noise Control in
Office Buildings and Homes," Noise Reduction, L.L.
Beranek, ed., McGraw Hill Book Co., Inc., New York,
Report
1594, op.
cit.,
Urban and
Table-10.
1960, Chapter 23,
33.
BBN Report
1505, op. cit.,
34.
Ibid.
35.
Hand Book of
Appendix II.
p.42.
Noise Measurement
-
1967,
op.
cit.,
178
CHAPTER V,
1.
Committee
2.
BBN Inc., Mimeographed notes on
parks and recreational areas.
3.
Committee
on
4.
BBN. Noise
in Urban
5.
BBN
6.
on
the
REFERENCES AND
the
Report No.
*Committee on
Problem of Noise,
&
op.
8.
Greater London Council,
9.
Committee
10.
on
the
op.
cit.,
op.
Problem of
Noise,
p.7.
-in
cit.
op.
Table-1
cit.,
Noise.
op.
&
p.
cit.
cit.
p.5.
Table-3.
3 2
op.
.
cit.,
p.32.
Simonson, Wilbur H.,
"Abatement of Highway Noise with
Special Reference to Roadside Design," H.R. Bulletin 105, Highway Research Board, Washington, D.C., 1955,
p.3.
11.
cit.,
cit.
Problem of
BBN
1594,
qp.
Suburban Areas,
7.
Report
op.
Highway Noise
Problem of Noise,
1505,
the
NOTES
BBN,
Report
1594,
op.
cit.,
Table-4.
179
REFERENCES
CHAPTER VI,
AND NOTES
1.
Voorhees, A. "Techniques for Determining Community
Values," Highway Research Board, Record-102,
Washington. D.C.
2.
M.I.T., Urban Systems Laboratory, "The Impacts
Highways Upon Environmental Values," op. cit.
3.
A.A.S.H.O., "A Policy
Highways - 1965," op.
4.
Design of
on Geometric
cit.
-A.A.S.H.O., "A Policy on Arterial Highways
Urban Areas" American Association of State
Officials, Washington, D.C., 1957.
5.
Highway Capacity Manual -
6.
A.A.S.H.O.
"A
Highways -
1965,"
Inc.,
7.
BBN
8.
Greater
on
Policy
1965,
Geometric
op. cit.,
Report No.
1594,
London Council,
op.
p.
op.
Rural
in
Highway
cit.
Design
of
Rural
194.
cit.,
p.17.
"Traffic Noise"
op.
cit.,
p.17.
9.
10.
BBN Inc. Mimeographed notes on
parks and recreational areas.
Simpson,
Wilbur H.,
op.
cit.,
of
Hiqhway Noise
op.cit.
p.3.
in
180
CHAPTER VII,
REFERENCES AND NOTES
1.
Maguire, Charles A., Associates, Report on Inner Belt
and Expressway System, Boston Metropolitan Area - 1962.
2.
This plan is used as a 'base map' for the hypothetical
schemes in this study, throuqh the courtesy of
from their preCharles A. Maguire Associates Inc.,
be reproduced
not
should
This plan
liminary studies.
in any form without their permission.
3.
pointed out that the traffic volumes used
and also Mainline
.in this study have been superceded,
at-grade schemes (ALTERNATES I and III) as presented
in this study are purely hypothetical to study various
noise conditions.
4.
should be
It
BBN
Mimeographed notes on highway noise
and recreational areas, op. cit.
Inc.,
parks
5.
Ibid.
6.
Highway
Capacity Manual
-
1965,
op.
cit.,
in
Fig.-3.7,
p.32.
7.
Commonwealth of Massachusetts, D.P.W.,
Unit Prices, by districts, for Highway
Contracts
8.
Preliminary
Maguire
9.
-
"Summary of
and Bridge
1968."'
Estimates
for
G.M. Type
Barrier,
C.A.
files.
Junkat, M.P. and Starrett, J.A., "Automobile Barrier
Impact Studies Using Scale Model Vehicles," Highway
Research Board, Record-174,"Washington, D.C., 1967,
p.
37
.
181
CHAPTER VIII
REFERENCES
AND NOTES
System Laboratory, "The Impacts
Environmental Values," op. cit.
of
1.
M.I.T., Urban
Highways Upon
2.
BBN
3.
Ibid.
4.
BBN
Inc.,
Report
5.
BBN
Inc.,
Report No.
6.
Appleyard, Lynch, Myer, "The View From the Road,"
M.I.T. Press, Cambridge, Massachusetts, 1964, p. 1 2 .
Inc.,
Report No.
1505,
1594,
op.
1505,
op.
cit.
cit.,
op.
Table-7.
cit.