ROAD SAFETY AUDIT
MAJOR HIGHWAY MEDIAN
CROSS-OVER CRASHES
ROUTE 140 TAUNTON-LAKEVILLE
Prepared for
Prepared by
MS Transportation Systems, Inc.
Framingham, Massachusetts
May 2009
ROAD SAFETY AUDIT
MAJOR HIGHWAY MEDIAN
CROSS-OVER CRASHES
ROUTE 140 TAUNTON-LAKEVILLE
Final Report
May 2009
Prepared for
Massachusetts Highway Department
Prepared by
MS Transportation Systems, Inc.
Consultant Engineers and Planners
300 Howard Street P.O. Box 967
Framingham, Massachusetts 01701
Tel: 508-620-2832 Fax: 508-620-6897
www.mstransportationsystemsinc.com
Route 140 Taunton-Lakeville Road Safety Audit
TABLE OF CONTENTS
Page
INTRODUCTION
1
RSA PROCESS
3
ANALYSIS
8
SUMMARY OF RSA FINDINGS/POTENTIAL ACTIONS
12
RECOMMENDATIONS
19
APPENDIX
22
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Route 140 Taunton-Lakeville Road Safety Audit
INTRODUCTION
Lane departure crashes are one of the primary fatal crash types in Massachusetts. The
Commonwealth exceeds the national average for the proportion of fatal lane departure
crashes and was designated a lead state in lane departure crashes by the American
Association of State Highway and Transportation Officials (AASHTO).
The
Massachusetts Highway Department (MassHighway) conducted a study of the problem
and found that during 2002-2004, lane departure crashes accounted for 25 percent of all
injury crashes and nearly half, 46 percent, of all fatal crashes.
As part of the effort in implementing the safety plan and specifically reducing lane
departure crashes, the MassHighway is completing a Road Safety Audit (RSA) Review
Project specifically focused on median crossing (or median cross-over) crashes on its
major highways. Road safety audits are a formal safety performance examination on
existing or future roadways by an independent audit team. These specific audits are
being conducted in locations where cross-over experience has been or has the potential
to be of concern and where the RSA team has judged that factors exist that could affect
the safety risk. During the audit, the RSA team works to identify opportunities for
enhancing safety and to recommend specific enhancements intended to reduce median
cross-over crashes and improve the overall safety along the highway.
A RSA was conducted as part of this project section of Route 140 Taunton-Lakeville and
Figure 1 shows the corridor section under study. The study section is from south of the
Stevens Street interchange (No. 11) in Taunton to the County Street interchange (No. 9)
in Lakeville. The study section also includes the Myricks Street (Route 79) Interchange
No. 10.
The purpose of this Route 140 Taunton-Lakeville RSA was to identify current conditions
on the highway section under study that could potentially affect safety risk and to
recommend a set of actions to address the identified safety factors. Recommendations
contained in this report reflect the overall consent of the RSA team and do not
necessarily reflect the official views of MassHighway.
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Page 1
Stevens Street
91
Forest Street
Int.
No. 11
140
Route 79
Int.
No. 10
Route 24
140
Highland
Avenue
Myricks Street
County Street
Int.
No. 9
Freetown
Street
- Interchange
N
Project Location
W
S
Route 140 Road Safety Audit
Taunton, Massachusetts
MS Transportation Systems, Inc.
E
1 : 25,000
Framingham, Massachusetts
FIGURE 1
Route 140 Taunton-Lakeville Road Safety Audit
RSA Process
The general process outlined in the guideline1 was essentially followed although with
some minor variations incorporated in the overall procedure. These were due in part to
the project location being a high speed, high volume section of an access controlled
highway. With these characteristics, there are limited areas to safely stop and gather as
a group along the section without potentially hindering traffic flow or the safety of the
project. Given the RSA team size (noted below) and general character with the corridor,
the team members who visited the site prior to the team meeting did so either
individually or in smaller groups. A video recording of a drive-thru in both directions was
collected by the RSA consultant and used at the meeting to review conditions as a
group. Background material and plans were transmitted to the RSA consultant to
compile and review prior to the initial RSA team meeting. Crash and traffic volume data
were transmitted to RSA team members prior to the meeting as well. Once the initial
RSA team meeting was conducted, the RSA consultant gathered the input, completed
the analysis and prepared a draft document for team members to review. Data including
summary crash records for the 2004-2007 period, two (2) detailed crash descriptions of
cross-over crashes, and available record highway plans were obtained and reviewed by
the RSA consultant.
•
RSA Team
The following individuals participated in the Route 140 Taunton-Lakeville Road Safety
Audit:
Edward C. Feeney, MassHighway District 5 Traffic
Timothy White, FHWA
Jim Hadfield, SRPEDD
Jackie Schmidt, SRPEDD
Timothy Kochan, MassHighway District 5 Planning
Erin Kinahan, MassHighway, District 5 Projects
Erin K. Sullivan, MSP Middleboro
Lisa Schletzbaum, MassHighway,
Safety Management Unit
Bonnie Polin, MassHighway, Safety
Xian Chen, MassHighway
Jessica Stanley, MassHighway
William J. Scully, MS Transportation
Systems (RSA Consultant)
Team members represented various agencies, disciplines and expertise.
•
RSA Meeting
A meeting was held on September 25, 2008 at the MassHighway District 5 Office. At
the meeting, the RSA consultant provided a brief overview of the RSA purpose, a
summary of the roadway section’s characteristics and the results of the review to date in
terms of geometry, volume and crash data researched and the field visit observations.
1
MS Transportation Systems, Inc., Road Safety Audits, Median Cross-Over Crashes, Audit Guidelines,
Prepared for MassHighway, October 2007.
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Route 140 Taunton-Lakeville Road Safety Audit
The RSA team members listed above were present at the meeting. The video record of
the Route 140, taken while driving the corridor was viewed. During and following the
video, additional discussions related to the possible factors related to the cross-median
crashes and possible solutions to prevent or alleviate similar characteristics in the future.
The RSA team provided input on the background supporting data and the key items
observed in the field and those items that were listed on the RSA Median Cross-Over
Prompt List.
Key items noted at the meeting included the following:
 Pavement surface appears old, with “scarring” and a large number of
skidmarks.
 The sense by the enforcement personnel was that speeds are generally in
excess of 70 mph even with fairly consistent enforcement.
 The RSA team members experienced with the corridor noted that fatigue may
be a factor in this study section and combined with “dark”, straight sections of
highway can contribute to the likelihood of an event or incident in the study
section.
 Vehicle queues at the Route 24 northbound ramp from Route 140 is
problematic although it may be improving with the recent Route 24
improvements.
 Guide signage is less than optimum for rest area and interchanges –
including the signage for Route 79 in the southbound direction.
 Deer crossings are common in this section.
Following the RSA meeting, the RSA consultant compiled the information, completed the
analysis and circulated the draft report to team members.
•
Analysis Procedures
As previously indicated, the RSA analysis generally followed the procedure described in
the previously referenced Guideline with some variations and also took into
consideration the methods published by the Federal Highway Administration2 (FHWA)
and those included in FHWA training materials3. The basic tasks included:
•
2
3
Obtaining and reviewing crash and other traffic characteristic data and
available record plans.
Federal Highway Administration, FHWA Road Safety Audit Guidelines, Publication No. FHWA SA-06-06,
Washington, D.C., 2006.
Federal Highway Administration, Resource Center, Road Safety Audits Mini-Workshop, Jeffrey Shaw, PE,
PTOE, presented to New England ITE Section, September 19, 2006.
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Route 140 Taunton-Lakeville Road Safety Audit
•
•
•
Conducting site reconnaissance and collecting a current record of condition
via photos and video,
Identifying potentially hazardous issues, and
Identifying and evaluating potential actions to address the noted issues.
In assessing the issues identified by the RSA Team, the relative seriousness and
potential risk relative to crash frequency and severity were determined. Using the
guidelines of FHWA4 as input and considering characteristics of this specific RSA, the
relative frequency criteria and severity criteria were identified and are presented in Table
1 and Table 2, respectively.
TABLE 1
FREQUENCY RATING
ESTIMATED
Exposure
high
medium
high
medium
low
high
Probability
high
high
medium
medium
high
low
low
medium
low
medium
low
low
EXPECTED CRASH FREQUENCY
(PER AUDIT ITEM)
5 or more crashes per year
FREQUENCY
RATING
Frequent
1 to 4 crashes per year
Occasional
Less that 1 crash per year, but
more than 1 crash every 5 years
Infrequent
Less than 1 crash every 5 years
Rare
Source: FHWA RSA Training Workshop
TABLE 2
SEVERITY RATING
Typical Crashes Expected
(per audit item)
Expected Crash Severity
High-speed crashes; head on and
rollover crashes
Moderate-speed crashes; fixed
object or off-road crashes
Crashes involving medium to low
speeds; lane changing or
sideswipe crashes
Crashes involving low to medium
speeds; typical of rear-end or
sideswipe crashes
Probable fatality or
incapacitating injury
Moderate to severe injury
Severity
Rating
Extreme
High
Minor to moderate injury
Moderate
Property damage only or
minor injury
Low
Source: FHWA RSA Training Workshop
4
Federal Highway Administration, Resource Center, Road Safety Audits Mini-Workshop, Jeffrey Shaw, PE,
PTOE, presented to New England ITE Section, September 19, 2006.
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Route 140 Taunton-Lakeville Road Safety Audit
Taking into consideration both frequency and severity, the relative risk of a particular
audit item was rated. The risk ratings are shown in Table 3. For each safety issue
identified, the potential seriousness of the issue as well as possible mitigation measures
have been indicated.
TABLE 3
CRASH RISK ASSESSMENT
Frequency
Rating
Low
Frequent
Occasional
Infrequent
Rare
Severity Rating
Moderate
High
C
B
A
A
D
C
B
A
Source: FHWA RSA Training Workshop
Crash Risk Ratings:
A: minimal risk level
B: low risk level
C: moderate risk level
•
Extreme
E
D
C
B
F
E
D
C
D: significant risk level
E: high risk level
F: extreme risk level
RSA Field Audit
Field audits were conducted prior to the RSA meeting held on September 25, 2008. The
field audits included several drive-thrus in each direction of travel as well as through the
interchanges. A Prompt List developed for median cross-over RSA’s was used for
guidance. The Prompt List is included in the Appendix. The following were noted during
the audit:
•
The study section consists of two travel lanes per direction.
•
The inside shoulder appears to be between 1 and 2 feet in width.
•
Rumble strips exist in both inside and outside shoulders.
•
The median is largely open, fairly wide and designed generally as a
“depressed” median.
•
The southbound direction is higher than the northbound direction.
•
Speeds are posted at 65 miles per hour.
•
There is no lighting along the section.
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Route 140 Taunton-Lakeville Road Safety Audit
•
There is a rest/parking area in both directions north of the Route 79
interchange (Interchange No. 10). At the time of the field audit, advance
signs for the parking areas and signage immediately at the areas were
limited. Subsequent to the field audit, new signs were installed providing
information between 1 and ½ mile in advance as well as at the facility itself.
•
Acceleration and deceleration lanes appear adequate in terms of length but
markings could be improved for guidance.
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Route 140 Taunton-Lakeville Road Safety Audit
ANALYSIS
Existing Conditions
Route 140 Taunton-Lakeville is a major highway that provides east-west movement in
Southeastern Massachusetts. Route 140 also serves the major cities of New Bedford
and Fall River as well as the regional shopping area and educational facilities in
Dartmouth. The section included in this study is approximately seven (7) miles in length
from just south of the Stevens Street interchange in Taunton to the County Street
(Interchange No. 9) in Lakeville. The photographs in Figures 2 and 3 show these
sections and the overall horizontal alignments.
The roadway in this area consists of two (2) travel lanes per direction. The roadway also
has a full (10 foot) outside shoulder and an inside shoulder largely in the range of 1 to 2
feet, Rumble strips have been installed on both the inside and outside shoulders. The
alignment is mostly straight with a few large radius curves and can be characterized as
“gentle”. It was noted that the speed limits are posted at 65 miles per hour (mph).
Including the Stevens Street interchange at the northern unit of the study section, there
are three interchanges in the study section. Interchange spacing is 2.6 miles or more.
The unpaved portion of the median is approximately 90 to 100 feet in width. The length
of the “open” median in the study section is approximately 5.3 miles. Figures 4 and 5
present photographs that depict the current conditions along the study section.
Figure 2 – Route 140 from Steven Street to
Route 79
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Figure 3 – Route 140 from Route 79 to
County Street
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Route 140 Taunton-Lakeville Road Safety Audit
As was noted in the field visits, the rest/parking areas on each side of the highway are
not ideally signed both in terms of advanced warning and more specific entry points and
the exit and merge locations.
Figure 4 – Route 140 Southbound
Figure 5 – Route 140 Northbound North of County Street Interchange
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Route 140 Taunton-Lakeville Road Safety Audit
A review of available safety data was completed as part of this RSA. The review of data
included crash data reported for the years 2004 to 2007. The summary table and spot
map are included in the appendix. Key aspects noted in the data included the following:
 A total of 24 median related crashes reported between 2004 and 2007 or
approximately 6 crashes per year.
 Of the total, 6 or 25% were cross-median crashes.
 The reported fatal crash was classified as a median crash.
 Based on the data available, eleven (11) of the 24 total reported median
related crashes occurred in close proximity to the interchange with Route 79.
 Approximately 63% of total reported median related crashes resulted in
personal injuries or fatalities. Five of the six cross-median crashes resulted in
personal injuries.
 Of the reported median – related crashes, half were initiated in the
northbound direction. Four of the six cross-median crashes were initiated in
the northbound direction.
 Only four of the 24 crashes (16%) occurred under wet or icy surface
conditions.
 Half (50%) of the median related crashes were reported under dark (night)
conditions.
In assessing the characteristics of the crashes, there was no one reason that stood out
among the possible contributing causes. It is generally acknowledged that drivers may
leave the roadway as a result of the following four reasons:




Driver Error
Collision Avoidance
Roadway Condition
Vehicle Component Failure
High speeds were cited in three (3) crashes while five (5) crashes were at least partially
attributed to fatigue.
The traffic volumes on Route 140 in this section have been estimated at 35,000 on an
average weekday. Historical truck traffic count data were obtained from MassHighway
that showed a 3% truck percentage of the total volume for both the peak hour and daily
periods. This amounts to approximately 100 truck trips over the day.
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Route 140 Taunton-Lakeville Road Safety Audit
Figure 6
Route 140 Taunton-Lakeville Traffic Volume
In summary, the RSA has identified a number of physical and operational characteristics
as being a potential contributing factor to the safety issues although each with varied
levels of seriousness. The major one is:
¾ The median is open and although being relatively wide, the experience
indicates that it is highly crossable. In addition, whether the crash was
categorized as a cross-median or simply a median entry, most of the crashes
have resulted in personal injuries as well as one fatal crash.
The next section will discuss the key issues or factors identified by the RSA team and
the potential actions to consider for addressing them.
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Route 140 Taunton-Lakeville Road Safety Audit
Summary of RSA Findings/Potential Actions
Based on the field review, the review of crash data and discussions among the RSA
team members, the issues related to the safe operating conditions of the Route 140 in
the Taunton-Lakeville area were identified. There were a number of factors or issues of
concern that were identified as potentially having an effect on the risk and these are
listed in Table 4 along with the assigned risk rating.
TABLE 4
SUMMARY OF FACTORS THAT POTENTIALLY AFFECT
THE RISK OF SAFETY RELATED EVENTS
Factor or Issue
Risk Rating
Open, crossable median
E
Inside shoulder is narrow
C
Markings for deceleration and acceleration lanes were
less than optimum in terms of guidance
D
Rest area entry and exit – less than ideal warning or
guidance
C
Speeding and driver behavior is significant in section
C
Southbound sign for Route 79 placement inadequate
B
Dark, unlit corridor that is long and straight
C
Driver fatigue
C
As shown in Table 4, there are number of risk factors that have been identified that
potentially contribute to cross-median crashes. Included in this listing is the “open”
median. While the median is fairly wide, there have been a relatively high proportion of
total median related crashes being actually cross-median crashes. The risk rating
assigned to this factor was ‘E’ in this case due to the frequency of median entries, crossmedian crashes and the potential of very severe results of the cross-median crashes.
Other factors include the inside shoulder being less than the 4 feet minimum width
although in the Route 140 Taunton-Lakeville section, it is wide enough to support the
rumble strip. However, a four foot wide shoulder would provide a greater chance of
recovering within the paved area. A rating of ‘C’ was assigned to this factor.
The markings for the acceleration/deceleration lanes were found to be less than ideal
and a rating of ‘D’ was assigned to this factor. Inadequate markings in the areas of the
interchange including deteriorated markings or markings that result in the perception that
lanes are not sufficiently long. A rating of ‘C’ was assigned for the factor related to
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Route 140 Taunton-Lakeville Road Safety Audit
exiting from the parking areas as it could result in inappropriate lane changing in the
merge area although the general visibility along the highway in these areas is fairly
good. This can influence the motorists behavior in a negative way resulting in “quick
lane-changing”. The RSA team also noted the high speeds/driver behavior in the
section as being a contributing factor to median entries and affecting the risk of crossmedian crashes. This factor was assigned a rating of ‘C’.
Signage is also less than ideal relative to the Route 79 (or County Street) interchange,
particularly in the southbound direction approaching the exit. Similar to the signage at
the parking areas, this factor was rated a ‘B’.
The last set of risk factors noted by the RSA team members familiar with the corridor
was that this highway section is a notably dark corridor in the non-daylight hours.
Without such items as adequate route delineation or advance guide signage, the dark
route, which also has long, straight sections, can contribute to negative effect of driver
fatigue (factor) and an increasing chance of run off road crashes. These factors were
given a rating of ‘C’.
Suggested actions identified are intended to reduce all crashes on the Route 140 and/or
reduce the severity of the crashes were identified based on the specific issue. The
following paragraphs include discussion pertaining to the issues and the potential
actions to consider for implement. Given that this RSA program is focused on crossmedian crashes, median barriers were first evaluated. Additional actions are outlined
later in the report.
•
Consideration of a Median Barrier
One of the more significant actions to be considered is to install median barriers in the
current “open” areas. A barrier can be considered when there is a higher than desirable
chance or a greater risk for median cross-over crashes to occur and that have or could
result in fatalities and/or a high proportion of injury related crashes. In addition, a barrier
could be considered when the consequences or severity of a crash without a barrier are
worse than if the barrier were in place.
Factors that generally come into play in deciding on whether a median should be
installed involve the following:
 High volumes and speeds
 Truck volumes and mix
 Narrow median
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 History of cross-median crashes
 High risk of catastrophic event
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Route 140 Taunton-Lakeville Road Safety Audit
These items have been reviewed relative to the Route 140 section under study. Figure
7 presents a review of the corridor in relation to the median warrant criteria presented in
the AASHTO RDG5. As can be seen in the diagram with the median width (as measured
from edge line to edge line) is 100 feet and an estimated volume of 35,000 vehicles on
an average day, the intersection of the two items is in the area of the chart where it is to
the right of “barrier optional”.
As shown in the chart, the intersecting point falls to the right of the chart “barrier
optional”. In addition to the chart and related warrant criteria, which is a guideline,
further consideration was given to the following:
ƒ
ƒ
ƒ
One-quarter of all the reported median entry crashes in the four (4) year
analysis period were classified as cross-median.
Most (83%) of the cross-median crashes resulted in personal injuries.
A significant number of median related crashes were attributed in part to
fatigue.
Consequently, based on the above findings, the analysis of the data, the field drive-thru
and discussion of the conditions by the RSA team members, it was suggested that a
median barrier be considered for installation in the section of Route 140. The selection
of the barrier is discussed in greater detail in the next section followed by the complete
set of Route 140 RSA recommendations.
A. Barrier Selection
Once a decision is made to install a barrier, the type must be determined. There are a
number of barrier types that can be considered in addressing the median cross-over
crashes. These include the following:
♦
♦
♦
♦
Weak post W-Beam
Box Beam
Generic Low Tension Cable
High Tension Cable Barrier
♦ Strong post W-Beam
♦ Thrie Beam
♦ Concrete (Jersey)
In deciding on the type of barrier, there are a number of criteria suggested in the
AASHTO Roadside Design Guide. These criteria used in selecting a barrier type are
listed in Table 5.
5 American Association of State Highway and Transportation Officials, Roadside Design Guide,
Washington, D.C., 2002, Chapter 6 Update 2006.
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80
AVERAGE DAILY TRAFFIC
(thousands)
70
BARRIER
RECOMMENDED
60
BARRIER
CONSIDERED
50
median width
100 feet - ADT
35,000
40
30
BARRIER
OPTIONAL
20
10
0
0
10
20
30
40
50
60
70
MEDIAN WIDTH
(feet)
SOURCE: AASHTO ROADSIDE DESIGN GUIDE CHAPTER 6 UPDATE
Analysis of Median Barrier Warrant
Route 140 Road Safety Audit
Taunton-Lakeville, Massachusetts
MS Transportation Systems, Inc.
Framingham, Massachusetts
Figure 7
Route 140 Taunton-Lakeville Road Safety Audit
TABLE 5
CRITERIA FOR BARRIER SELECTION
Criteria
Comments
1. Performance Capability
Barrier must be structurally able to contain and redirect
design vehicle.
Expected deflection of barrier should not exceed available
deflection distance.
Slope approaching the barrier and distance from traveled
way may preclude use of some barrier types.
2. Deflection
3. Site Conditions
4. Compatibility
5. Cost
6. Maintenance
A. Routine
B. Collision
C. Material Storage
D. Simplicity
7. Aesthetics
8. Field Experience
Barrier must be compatible with planned end anchor and
capable of transitioning to other barrier systems (such as
bridge railings).
Standard barrier systems are relatively consistent in cost,
but high-performance railings can cost significantly more.
Few systems require a significant amount of routine
maintenance.
Generally, flexible or semi-rigid systems require
significantly more maintenance after a collision than rigid
or high-performance railings.
The fewer different systems used, the fewer inventory
items/storage space required.
Simpler designs, besides costing less, are more likely to
be reconstructed properly by field personnel.
Occasionally, barrier aesthetics are an important
consideration in selection.
The performance and maintenance requirements of
existing systems should be monitored to identify problems
that could be lessened or eliminated by using a difference
barrier type.
Source: AASHTO, Roadside Design Guide, 2002, Chapter 5 Roadside Barriers.
Based on extensive research and trials over the past five years, the high tension cable
barrier system has become more prominent in the U.S. The cable (flexible) barrier has
its advantages from a cost and aesthetic perspective, over the various guardrail systems
or concrete barrier. The median slope and/or recovery area also affects the use and
placement of any barrier including guardrail.
In addition to the cable barrier systems, the alternative types of guardrail were reviewed
for potential application on this route. Considerations included the volume of traffic,
relative amount of truck traffic and travel speeds. Based on these, the most applicable
types of guardrail for this route include the W-beam with strong post or the strong post
thrie-beam. These rails are appropriate for high speed highways and high volumes with
a relatively high proportion of truck traffic. Costs for each are somewhat similar though
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Route 140 Taunton-Lakeville Road Safety Audit
the thrie-beam has a higher cost. The weak post W-beam and box beam can be
eliminated due to the slope and type of highway. The concrete barrier would generally
be applicable in urban sections with limited median widths available. As a result of this
review, it was determined that the median barrier options that are most valid for
consideration for Route 140 in this section are the cable barrier and strong post guard
rail.
Maintenance issues are also an important consideration in decisions regarding median
barrier installations. The maintenance issues that are of concern include:
ƒ
ƒ
ƒ
ƒ
ƒ
ƒ
ƒ
Barrier hits per mile
Frequency of hits
Cost recovery
Cable downtime
Repair effect on traffic
Maintaining tension with cable system
Mowing median
Final selection of the barrier type should be based on the costs, physical condition of the
median, the ability to maintain a recovery zone, likely maintenance or repair
requirements, and compatibility with future planned pavement widening. In this case of
Route 140 in Taunton-Lakeville, it appears that a barrier could be placed in the median
leaving an adequate recovery zone and would have minimal effect on traffic if repair or
maintenance is required. The key points of the cable barrier and guardrail systems are
summarized below.
Cable Barrier
While the low tension generic cable system has been in existence for more than 50
years, most of the recent cable system research and installation is focused on the high
tension systems. There are currently six (6) manufacturers with systems approved by
the Federal Highway Administration (FHWA) for use under certain conditions. Research
on these types of barriers is ongoing. There are 3-rope or 4-rope cable systems as
shown in the following two photographs.
This barrier type can be installed on slopes of 6:1 or flatter with little constraint on
placement. There are certain systems (eg. Brifen and Gibraltor 4 rope) that have been
approved for slopes as steep as 4:1 as of this writing.
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Route 140 Taunton-Lakeville Road Safety Audit
4 – Rope Brifen System on I-495
3 Cable CASS System on Route 213
Guardrail
The guardrail could be placed in the median where slopes are 10:1 or flatter as well as
at the edge of a steep slope or where minimal recovery zones exist. With the guardrail
placed within several feet of the pavement edge, a clear zone (or recovery area) would
be eliminated at least on one side of the median if guardrail is applied on only one side
of the median. In some locations where the topography of the median is fairly flat, it may
be possible to install a single line of double faced barrier a greater distance from the
pavement edge in this specific project area.
Estimated per mile costs of the basic types of median barrier treatment to be considered
for this route are summarized in Table 6. Shown in the table are estimated per mile
costs of installing a cable barrier, a double faced W-beam guardrail and a double faced
thrie-beam guardrail. As can be seen, the cable barrier is expected to be the lower cost
option. The W-beam rail is a lower cost option compared to the thrie-beam, however,
there is slightly greater deflection with the W-beam.
TABLE 6
COMPARISON PER MILE COSTS
Cable vs. Guardrail
Costs/Mile
Cable
$144,000
W-beam
$171,000
Thrie beam
$213,000
For comparison, installing a Cable Barrier System in the 5.3 mile section east of Route
140 would cost approximately $763,200.
The thrie-beam guardrail would cost
approximately $1.13M.
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Route 140 Taunton-Lakeville Road Safety Audit
Recommendations
As a result of the RSA analysis and team input, a set of recommendations have been
identified and are summarized in Table 7. These actions are intended to reduce the
chance of cross-median crashes, reduce the severity of all crashes and improve the
overall safety condition of this section of Route 140 in Taunton and Lakeville.
Identified in the table in addition to the risk factor and recommended action are the
estimated costs and potential timeframe (i.e. short (0-1 year), medium (1-3 years) and
long (>3 years)).
The major recommendation for the Route 140 section in Taunton-Lakeville is to install a
median barrier in the highway section under study. It is estimated that 5.3 miles of
median barrier would be installed from immediately south of Stevens Street to the
County Street interchange. The barrier should be placed close to the center of the
median leaving a clear and adequate width for recovery. This action is estimated to be a
medium-term action given the existing condition of the median and the length of barrier
required. A preliminary estimate of cable barrier for this section is $763,200.
TABLE 7
SUMMARY OF RECOMMENDATIONS
Risk Factor
Risk
Rating
Recommended
Action
Estimated
Cost
$763,2001
Estimated
Timeframe
Open, crossable median
E
ƒ Install barrier –
approx. 5.3 miles
ƒ medium
term
Inside shoulder is narrow
C
ƒ Widen shoulder
TBD
ƒ long term
Markings for acceleration lanes
were less than desirable
D
ƒ Modify markings –
extend length of
lanes
TBD
ƒ short term
Rest area entry and exit – less
than ideal warning or guidance
C
ƒ modify markings
ƒ Add signs
TBD
$3,000
ƒ short term
ƒ short term
Speeding and driver behavior
is significant in section
C
ƒ Increase
enforcement
TBD
ƒ short term
Southbound sign for Route 79
placement inadequate
B
ƒ Install additional
sign ½ mile in
advance of exit
$3,000
ƒ medium
term
Dark, unlit corridor
C
ƒ Upgrade/install
new reflector posts
along median
$11,000
ƒ short term
Driver fatigue
C
ƒ Install electronic
VMS signage
TBD
ƒ medium to
long term
1) assumes cable barrier
MS Transportation Systems, Inc.
Page 19
Route 140 Taunton-Lakeville Road Safety Audit
The inside shoulder was noted as being 1-2 feet width and is recommended to be
widened. However, this is more of a long-term action that would be completed as part of
the overall rehabilitation or resurfacing project was undertaken. Accomplished as part of
a larger rehabilitation project results in a relatively small incremental cost. As part of that
future work, the rumble strip would need to be reinstalled as well.
The remaining recommendations represent relatively low cost, short term actions that
can be taken to enhance awareness, guidance and better driver behavior in the section
under study. These include:
•
Improving the markings for the acceleration-deceleration lanes. An example
of the deceleration lane is shown in Figure 8 using dotted lines. These are
low cost actions that can be done at the time of normal pavement marking
maintenance. The current MUTCD depicts options with dotted lines for
deceleration lanes. The upcoming revised MUTCD is expected to include
dotted lines for acceleration lanes as well.
•
Installing or upgrading reflective in pavement markers and delineator posts
along the route to alleviate the “darkness” sense and provide improved
guidance to motorists. These are low cost actions.
•
Increasing the emphasis on consistent and high level police presence and
speed enforcement.
•
Using electronic variable message signs (VMS) to inform motorists of
roadway/traffic conditions and relevant safe driving information. Through the
use of VMS, it may also assist in “breaking up” the monotony to the driver on
this long, fairly straight and “dark” corridor.
•
Lastly, installing an additional sign in the southbound direction in relation to
the exit for Route 79 (Myricks Street) to provide adequate, clear notice.
MS Transportation Systems, Inc.
Page 20
a-Parallel
deceleration lane
b-Tapered
deceleration lane
Neutral
area
Optional
chevron
markings
Channelizing
lines
Theoretical gore
point
Channelizing
lines
Broken lane
markings for
one-half of
full-width
deceleration
lane
Optional
dotted
extension of
lane line
Legend
Direction of
travel
Source: Based on MUTCD Figure 3B-8
Note: Conceptual illustration only
Potential Pavement Markings - Off-Ramp Diverge
Locations - Examples of Channelizing Line
Applications for Exit Ramp Markings
Route 140 Road Safety Audit
Taunton-Lakeville, Massachusetts
MS Transportation Systems, Inc.
NOT TO SCALE
Framingham, Massachusetts
FIGURE 8
Route 140 Taunton-Lakeville Road Safety Audit
Appendix
•
•
•
•
MS Transportation Systems, Inc.
RSA Meeting Agenda
RSA Meeting Attendees
Median Crash Diagram
Crash Summary Data
Page 22
Road Safety Audit
Taunton/Lakeville – Route 140
Meeting Location: MassHighway District 5 Office
1000 County Street, Taunton
Thursday, September 25, 2008
11:00 AM – 12:30 PM
Type of meeting:
Cross Median – Road Safety Audit
Attendees:
Invited Participants to Comprise a Multidisciplinary Team
Please bring:
Thoughts and Enthusiasm!!
11:00 AM
Welcome and Introductions
11:15 AM
Introduction to Road Safety Audits and Cross Median Crashes
11:30 AM
Review of Site Specific Material
• Crash Summary– provided in advance
• Existing Geometries and Conditions
• Video and Images
12:00 PM
Completion of RSA
• Identification of Safety Concerns – using RSA Prompt List as a guide
• Identification of Possible Countermeasures
12:30 PM
Adjourn for the Day – but the RSA has not ended
Instructions for Participants:
• Before attending the RSA on September 25th participants are encouraged to drive
Route 140 in Taunton/Lakeville (Interchanges 9-10) and complete/consider
elements on the RSA Prompt List with a focus on safety factors affecting cross
median crashes.
• All participants will be actively involved in the process throughout. Participants
are encouraged to come with thoughts and ideas, but are reminded that the
synergy that develops and respect for others’ opinions are key elements to the
success of the overall RSA process.
• After the initial RSA meeting, participants will be asked to comment and respond
to the document materials to assure it is reflective of the RSA completed by the
multidisciplinary team.
ROAD SAFETY AUDIT MEETING
Route 140 Taunton-Lakeville September 25, 2008
MassHighway District 5 Offices, Taunton MA
Attendance List
Name
Agency/Dept.
Email
Bill Scully
MS Transportation Systems, Inc.
bscullyjr@mac.com
Edward C. Feeney
MHD
edward.feeney@mhd.state.ma.us
Erin K. Sullivan
MSP Middleboro
erin.sullivan@state.ma.us
Xian Chen
MHD
xian.chen@mhd.state.ma.us
Jessica Stanley
MHD
jessica.stanley@mhd.state.ma.us
Lisa Schletzbaum
MHD - Safety
lisa.schletzbaum@mhd.state.ma.us
Tim White
FHWA
timothy.a.white@fhwa.dot.gov
Bonnie Polin
MHD - Safety
bonnie.polin@mhd.state.ma.us
Timothy Kochan
MHD - District 5
timothy.kochan@mhd.state.ma.us
Jim Hadfield
SRPEDD
jhadfield@srpedd.org
Jackie Schmidt
SRPEDD
jschmidt@srpedd.org
Erin Kinahan
MHD
erin.kinahan@mhd.state.ma.us
MS Transportation Systems, Inc.
CT
ST R
EET
T
C IN
M
AI
N
ST
R
PR E
EE
±
Route 140 Median Crashes
1
2
TA U N T O N
3
"
)
10
YR
KS
S
EE
T
LAKEVILLE
BED
R D ST R
EE
T
FO R
PAD EL F
O
M
IC
TR
)
"
)
"
EET
140
79
BERKLEY
TR
DS
12
13
Crash IDs
between 4 - 11
14
RO
AD
15
HI
GH
LA
ND
16
17
Legend
Type of Median Crash 2004 - 2007 * Major Roads
Cross Median, Non-Fatal Crash
Interstate
Median, Fatal Crash
Principal Arterial
Median, Non-Fatal Crash
Minor Arterial
Municipal Boundary
Collector
L AN D
H OW
RO A
D
* 2007 crash file has not yet been closed.
0.25
0.5
0.75
Miles
1
HO
W
LA
TY
18
S TR
EE
T
19
EE T
20
ND
RO
AD
FR E E T O
W N S TR
Local
0
CO
UN
21 22
23
"
)
9
MASSACHUSETTS HIGHWAY SAFETY DIVISION
CRASH SUMMARY
ROADWAY:
Rt. 140
STUDY PERIOD:
NO.
CITY:
1/1/2004
CRASH DAY
CRASH NUMBER
TO
12/31/2007
TIME OF DAY
CRASH DATE
Taunton / Lakeville
LOCATION: South of Exit 10
TRAVEL
LIGHT
WEATHER
ROAD
REASON FOR
VEHICLE
MEDIAN OR CROSS
DRIVER CONTRIBUTING
CRASH
DIRECTION
CONDITION
CONDITION
SURFACE
RUNNING OFF ROAD LEFT
MOVEMENT
MEDIAN CRASHES
CAUSE
SEVERITY
1
1927850
Tuesday
9:28 PM
04/05/05
NB
Dark-Not lighted
Clear
Dry
Vehicle 2 tried to pass vehicle 1 but drifted into it due to driver distraction; both vehicles spun out into the median
Right travel lane into median
Median
Failure to keep in proper lane
Non-Fatal Injury
2
1992868
Sunday
1:25 AM
09/18/05
NB
Dark-Not lighted
Cloudy
Wet
Vehicle was struck by an unknown passing vehicle causing the driver to spin out of control coming to rest in the median
Left travel lane into median
Median
Driving too fast for conditions
Non-Fatal Injury
3
1806112
Thursday
6:15 AM
04/29/04
NB
Daylight
Clear
Dry
Driver was passing another vehicle and hit it then spun out across the median ending in the SB right ditch
NB left lane across median, across all SB lanes into right-hand ditch
Cross Median
Made an improper turn
Non-Fatal Injury
4
2149220
Friday
2:00 AM
01/19/07
SB
Dark-Not lighted
Rain
Wet
Driver was on cell phone and drifted off the road to the left and then struck the left guardrail and spun across all SB lanes
Right travel lane into median and guardrail
Median
Not reported
Non-Fatal Injury
5
1928310
Friday
7:25 PM
06/17/05
SB
Daylight
Clear
Dry
Vehicle was passed on the right causing the driver to swerve and lose control and spin out into another car and then into the median
Left travel lane into median
Median
No improper driving
Non-Fatal Injury
6
2051337
Saturday
12:00 AM
03/25/06
SB
Dark-Not lighted
Sleet, hail
Wet
Driver fell asleep and drifted into the left guardrail then came to final rest in the median
Left travel lane into median guardrail and into median
Median
Fatigued/Asleep
Property Damage Only
7
1993306
Monday
9:40 AM
12/05/05
NB
Daylight
Cloudy
Dry
Driver lost control of vehicle for unknown reason and traveled across the median and across all SB lanes into SB right shoulder
NB left travel lane across median, across all SB lanes into right-hand shoulder
Cross Median
Failure to keep in proper lane
Non-Fatal Injury
8
2244137
Thursday
7:07 AM
08/16/07
NB
Daylight
Clear
Dry
Driver crossed the median for unknown reason and struck a vehicle traveling in SB left lane
NB left travel lane across median into SB left travel lane
Cross Median
Not reported
Non-Fatal Injury
9
2051299
Saturday
4:10 AM
03/11/06
SB
Dark-Not lighted
Clear
Dry
Driver fell asleep and entered median and traveled down the embankment onto Rt. 79
Left travel lane into median and down embankment
Median
Fatigued/Asleep
Non-Fatal Injury
10
2249476
Friday
2:13 PM
11/09/07
SB
Daylight
Clear
Dry
Driver drifted onto the left rumble strip and over-corrected and then lost control of the vehicle and it went onto the median and rolled over
Left travel lane into median
Median
Over-correcting/over-steering
Fatal Injury
11
2016168
Tuesday
5:20 AM
01/03/06
NB
Dark-Not lighted
Snow
Snow
Driver lost control of slippery road and spun into the left guardrail
Left travel lane into guardrail
Median
Driving too fast for conditions
Property Damage Only
12
2095525
Thursday
6:45 PM
07/20/06
SB
Daylight
Clear
Dry
Driver hit rumble strip and over-corrected and eventually spun out into the median and rolled over and crossed all NB lanes
SB left lane across median and across all NB lanes into right guardrail
Cross Median
Failure to keep in proper lane
Non-Fatal Injury
13
2051368
Wednesday
2:31 AM
04/05/06
NB
Dark-Not lighted
Clear
Dry
Driver swerved to avoid a deer and entered the median and rolled over
Left travel lane into median
Median
Failure to keep in proper lane
Non-Fatal Injury
14
2067951
Sunday
7:32 AM
03/05/06
NB
Daylight
Clear
Dry
Driver swerved to avoid a deer and entered the median strip then lost control of the vehicle and spun across all NB lanes and flipped over
Right travel lane into median
Median
Fatigued/Asleep
Property Damage Only
15
1888848
Friday
11:20 PM
10/29/04
NB
Dark-Not lighted
Cloudy
Dry
Vehicle veered into median then back across all NB lanes into right shoulder
Left travel lane into median then across all NB lanes
Median
Failure to keep in proper lane
Property Damage Only
16
1889330
Friday
2:40 AM
11/19/04
NB
Dark-Not lighted
Clear
Dry
Driver was distracted or may have fallen asleep and the vehicle crossed the median and all SB lanes and struck a tree in the right shoulder
NB right lane across median into SB right shoulder
Cross Median
Failure to keep in proper lane
Property Damage Only
17
2132494
Thursday
7:47 AM
11/23/06
SB
Daylight
Rain/Cloudy
Wet
Driver moved left due to a close passing car and a tire went into the median causing the driver to lose control and vehicle struck trees
Left travel lane into median
Median
Failure to keep in proper lane
Non-Fatal Injury
18
1885808
Thursday
6:00 AM
01/27/05
SB
Dark-Not lighted
Snow
Snow
Driver lost control of vehicle due to conditions and entered the median and flipped over
Left travel lane into median
Median
Driving too fast for conditions
Non-Fatal Injury
19
2015892
Wednesday
2:21 PM
02/01/06
NB
Daylight
Cloudy
Dry
Vehicle was struck from behind causing it to spin out and come to rest in the median
Right travel lane into median
Median
Followed too closely
Property Damage Only
20
1993367
Saturday
8:20 AM
12/10/05
NB
Daylight
Clear
Snow
Driver lost control of vehicle while passing in the left lane and struck a tractor trailer then spun out into the median
Left travel lane into median
Median
Driving too fast for conditions
Property Damage Only
21
2228118
Monday
4:30 PM
06/25/07
SB
Daylight
Clear
Dry
Driver was attempting to avoid a vehicle that swerved into the lane and struck other vehicle and spun out in to median
Left travel lane into median
Median
Not reported
Property Damage Only
22
2225187
Friday
10:58 PM
06/22/07
SB
Dark-Not lighted
Clear
Dry
Driver was not paying attention and rear ended another vehicle and then veered across the median and across NB lanes to shoulder
SB right travel lane across median across NB lanes into right shoulder
Cross Median
Not reported
Non-Fatal Injury
23
2058028
Thursday
1:01 PM
04/20/06
SB
Daylight
Clear
Dry
Driver swerved to avoid unknown object in road and then lost control of the vehicle and slid into the median
Left travel lane into median
Median
No improper driving
Property Damage Only
24
2114326*
Sunday
2:45 AM
10/01/06
NB
Dark-Not lighted
Clear
Dry
Driver went into the median for unknown reason and the vehicle rolled over several times
Left travel lane into median
Median
Operating in erratic, reckless, aggressive manner
Non-Fatal Injury
* Could not be located
LIGHT CONDITION
TOTAL NO.
WEATHER CONDITION
DAYLIGHT
DARK NOT LIGHTED
CLEAR
CLOUDY
RAIN
24
12
12
15
4
2
3
100%
50%
50%
63%
17%
8%
13%
DRY
WET
17
4
3
71%
17%
13%
MADE IMPROPER
TURN
NO IMPROPER
DRIVING
NOT REPORTED
TOTAL NO.
MEDIAN OR CROSS MEDIAN
SNOW/SLEET
ROAD SURFACE
CRASH SEVERITY
MEDIAN
CROSS MEDIAN
FATAL
NON-FATAL INJURY
PROPERTY DAMAGE
ONLY
24
18
6
1
14
9
100%
75%
25%
4%
58%
38%
TOTAL NO.
FAILURE TO KEEP IN PROPER
LANE
SNOW/ ICE
DRIVER CONTRIBUTING CAUSE
FATIGUED/ASLEEP
FOLLOWED TOO
CLOSELY
OVER-CORRECTING/ OVER- DRIVING TOO FAST
STEERING
FOR CONDITIONS
OPERATING VEHICLE IN AN ERRATIC, CARELESS, AGGRESSIVE. MANNER
24
7
3
1
1
4
1
2
4
1
100%
29%
13%
4%
4%
17%
4%
8%
17%
4%
2007 CRASH INFORMATION IS NOT COMPLETE
CRASH SUMMARY IS BASED ON CRASH REPORTS WITH STATE POLICE NARRATIVES