Transportation Engineering
Contents
 History of transportation
 Current U.S. state of transportation
 Careers in transportation
 Transportation education curriculum
 The future of transportation
History of Transportation
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The first pipeline in the US was introduced
in 1825
First railroad opened in 1825
The internal combustion engine was
invented in 1866
The first automobile was produced in 1886
(by Daimler and Benz)
The Wright brothers flew the first heavierthan-air machine in 1903
History of Transportation
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The first diesel electric locomotive
was introduced in 1921
Lindbergh flew over the Atlantic
Ocean to Europe in 1927
The first diesel engine buses were
used in 1938
The first limited-access highway in
the US (the Pennsylvania Turnpike)
opened in 1940
History of Transportation
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The interstate highway system was
initiated in 1950
The first commercial jet appeared in
1958
Air transportation
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Commercial air transportation began in 1914 when
the St. Petersburg-Tampa Air Boat Line briefly
carried the first scheduled paying passengers
across Tampa Bay, Florida
After 1926, the airlines were created to carry first
the air mail and later passengers in regular service.
By World War II, the United States had a welldeveloped modern network of air routes and
airlines linking every state and reaching across
the oceans.
Air transportation
From Douglas
M-2 in 1920s 
To Being 777
in 2000s
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Automobile History
General Motors offered air bags in the 1973
model Chevrolet as an option. By 1988,
Chrysler became the first company to offer air
bag restraint systems as standard equipment.
In 1994, TRW began production of the first
gas-inflated air bag.
 The first car with an actual cooling system
was the 1940 model year Packard. In 1953
General Motors, Chrysler and Packard each
introduced an air conditioning system.
 In 1901, British inventor Frederick William
Lanchester patented disc brakes.
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Automobile History
In 1929, American Paul Galvin, the head of
Galvin Manufacturing Corporation, invented the
first car radio.
 Cruise control was first offered in the 1958
Chrysler Imperial, New Yorker and Windsor car
models.
 In 1854, Samuel McKeen of Nova Scotia
designed the first version of the odometer, a
device that measures mileage driven.
 In 1904, a car called the Christie featured a tire
on a mountable rim. The tire and rim could be
removed to allow the motorist to repair a flat
along the roadside.
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Automobile History
 Power
steering became commercially
available by 1951.
 Buick introduced the first electric turn signals
in 1938.
 Volvo had the first safety belts in 1849.
 Mary Anderson invented the windshield
wiper. Anderson was issued a patent for the
wipers in 1905. The wipers were standard
equipment on all American cars by 1916.
Current State Transportation
A look at transportation statistics
 A look at crash statistics
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Careers in Transportation
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What transportation engineers do
Transportation Topics
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Geometric design of highways
Highway/intersection capacity studies
Highway safety studies
Traffic control devices
Traffic flow characteristics
Urban transportation planning
Access management / Traffic calming
Pavement design
What are the four elements interacting on the roadway?
(i) Road user (or the human element)
(ii) Vehicle
(iii) Roadway
(iv) Traffic control device
Definition of the road users
The road users are defined as drivers, passengers, bicyclists, and
pedestrians who use streets and highways
What are road user characteristics?
(i) Senses: the driver can receive useful information regarding the
safe control of the vehicle through feeling, seeing, hearing, and
smelling.
(ii) Mind and nerves: by which the driver learns, decides, and
connects his/her senses with the muscles. These are intelligence,
judgement of space and motion, and coordination of bodily
movements.
(iii) Bones and muscles: by which the driver directs and controls
his/her vehicle and moves his/her body. These are the stature to fit
vehicle and its controls, limbs to connect with and operate regular and
special controls, and body movements.
Seeing or (visual perception)
The principle characteristics of the eye are visual acuity, peripheral
vision, color vision, glare vision and recovery, and depth perception.
Visual acuity is the ability to see fine details clearly. The most acute
vision is within a narrow cone of 30-50, fairly clear sight within
100-120.
Peripheral vision is the ability of a driver to see objects beyond the
cone of clearest vision.
Color blindness is the reduced ability to distinguish between red and
green. It is estimated that 8% of all men and 4% of all women
suffer some degree of color blindness.
Glare vision and recovery is important in designing and locating street
lighting, median barriers, tunnel lights.
Perception-and-reaction process (PIEV theory)
The driving task is a continuous series of sensory cues that the
motorist must monitor and respond to. The perception of, and
reaction to, a particular cue or stimulus involves four distinct
actions on the part of the driver:
i. Perception: The recognition or realization that a cue or stimulus
exists that requires a response
ii. Intellection or identification: The identification or interpretation of
the cue or stimulus
iii.Emotion or decision: The determination of an appropriate response
to the cue or stimulus
iv. Volition or reaction: The physical response that results from the
decision
Consider a typical example of a driver approaching a STOP sign. The
driver first sees the sign (perception), then recognizes it as a STOP
sign (intellection), then decides to STOP (emotion), and finally
puts his or her foot on the brake (volition).
Why is perception-reaction time important in design?
(i) Used to determine safe stopping distance
(ii) Used to determine minimum sight distance
(iii) Used to determine the length of the yellow phase at a signalized
intersection
See Figure 3-2 (McShane&Roess) for 85th-percentile perceptionreaction time
AASHTO recommends a perception-reaction time of 2.5 seconds for
design
What is the Distance Traveled During
Perception-Reaction Time?
Distance (d) = Speed (v) x time (t)
d in feet, v in ft/sec, and t in seconds
Example: Given: t=2.5 seconds and v=55 mph
Find: d
Solution: d = v . T = 55 x 1.47 x 2.5 = 202 ft.
What are important vehicular characteristics
considered in design?
i. Length
ii. Width
iii. Height
iv. Wheelbase
v. Weight
vi. Acceleration/deceleration
vii. Speed
viii. Tire friction
See table for details
Type of trucks on highways
Minimum turning path
What are the four basic elements of geometric design?
a. Horizontal alignment
b. Vertical alignment
c. Cross-section design
d. Channelization
Horizontal and vertical alignment are controlled by
two basic design criteria:
a. Design speed
b. Sight distance
Design speed
Design speed is defined as the maximum safe speed that can be
maintained over a specified section of a highway when conditions are
so favorable that the design features of the highway govern.
Sight distance
There are two types of sight distance used in designing highways:
a. Stopping sight distance
b. Passing sight distance
Stopping sight distance
Stopping sight distance is the distance required to see an object 6
inches high on the roadway. It is intended to allow drivers to stop
safely after sighting an object on the roadway large enough to
cause damage to the vehicle or loss of control
Passing sight distance
Passing sight distance is the distance required to see an oncoming
vehicle of a certain minimum size. A passing driver must have
sight distance to observe an oncoming vehicle at a distance
sufficient to allow him or her to enter the opposing lane, pass a
moving vehicle, and return to the travel lane safely. See Figure 3.2
(Banks) for illustration of passing distance.
Highway geometric design and visualization tools
Importance of signals
Signal timing fundamentals
Example of traffic calming
Intelligent Transportation Systems
Table 1-1: System Mileage Within the United
States (Statute miles)
a
Highway
b,c
Class I rail
c
Amtrak
d
Transit
Commuter rail
c
Heavy rail
Light rail
e
Navigable channels
f
Oil pipeline
1960
3,545,693
207,334
N
2000
3,936,229
99,250
23,000
N
N
N
25,000
190,944
U
U
U
26,000
U
Table 1-3: Number of U.S. Airportsa
1980
2001
TOTAL airports
15,161
19,306
Public use, total
4,814
5,315
% with lighted runways
66.2
75.9
% with paved runways
72.3
74.3
10,347
13,990
% with lighted runways
15.2
7.3
% with paved runways
13.3
32.0
15,161
19,306
730
635
Civil
N
562
Civil-Military
N
73
Private use, total
TOTAL airports
Certificatedb, total
Table 1-4: Public Road and Street Mileage in the United States
by Type of Surfacea (Millions of miles)
TOTAL paved and unpaved
1960
2000
3.546
3.950
Pavedb
Low and intermediate type
0.672
d
N
d
N
High-type
0.558
Paved total
1.230
2.504
2.315
1.446
c
Unpaved total
Table 1-12: U.S. Automobile and Truck Fleets by Use (Thousands)
1990
2000
15,196
2,889
2,950
538
551
249
141
990
883
317
306
136
1,581
U
1,173
7,346
Businessd
U
3,026
Governmentc
Utilities
Other (police, taxi, etc.)
Rental trucks (not vans and SUVs)
U
U
U
U
2,408
498
8
248
Number of trucks in fleets of 4 to 24
(4 to 9 trucks for 1999 and 2000)a
Total trucks in fleets
U
1,662
7,850
TOTAL automobiles and trucks in fleets
Number of automobiles in fleets of 25 or
a
more (10 or more cars for 1999 and 2000)
Businessb
Governmentc
Utilities
Police
Taxi (includes vans)
Rental (includes vans and SUVs)
Number of automobiles in fleets of 4 to 24
(4 to 9 cars for 1999 and 2000)a
Total automobiles in fleets
Number of trucks in fleets of 25 or
more (10 or more trucks for 1999 and 2000)a
Table 1-14: Retaila New Passenger Car Sales (Thousands)
1970
2000
TOTAL new passenger car sales
8,400
8,847
Domesticb
7,119
6,831
Japan
313
863
Germany
750
517
Other
217
637
1,280
2,016
Imports
Total
Signal Timing
1. Definitions
A signal cycle is one complete rotation through all of the indications provided
The cycle length is the time (in seconds) that it takes a signal to complete one full
cycle of indications. See Figure 8.7.
A phase is that part of a cycle allocated to a stream of traffic, or a a combination
of two or more streams of traffic, having the right of way simultaneously during
one or more intervals. See Figure 11.1.
An interval is any part of the cycle length during which signal indications do not
change.
The change interval is the total length of time in seconds of the yellow and allred signal indications. This time is provided for vehicles to clear the intersection
after the green interval. See Figure 8.6.
A “permitted” left turn is made across an opposing through vehicle flow. In such
cases, the driver is “permitted” to cross the opposing though flow, but must select
an appropriate gap in the opposing stream through which to turn.
A “protected” left turn is made without an opposing through vehicular flow. The
signal phasing “protects” left-turning vehicles by prohibiting the opposing
through movement.
Protected/Permitted or Permitted/Protected Left Turns: More complicated signal
phasing can be designed in which left turns (on a given approach or approaches)
have a protected turn for part of the cycle and a permitted turn for another part of
the cycle.
The peak-hour factor (PHF) is a measure of the variability of demand during the
peak hour and is given by:
Volume during peak hour
PHF 
4 x flow during peak 15 min within peak hour
The design hourly volume (DHV) is therefore given by:
DHV = Peak-hour volume / PHF. See Example 8.3
The passenger car equivalent (PCE) is a factor used to convert straight-through
volume of buses and trucks to straight-through volumes of passenger cars.
Turning movement factors are required because turning vehicles generally require
a longer green time than straight-through vehicles.
2. What is the objective of Signal Timing?
The main objectives of signal timing at an intersection are to reduce the average
delay of all vehicles and the probability of accidents. These objectives are
achieved by minimizing the possible conflict points when assigning the right of
3. Yellow Interval
The main purpose of the yellow indication after the green is to alert drivers to the
fact that the green light is about to change to red and to allow vehicles already in
the intersection to cross.
1. Definition
Intelligent Transportation Systems (ITS) is the application of modern computer
and communications technologies in transportation systems, resulting in
improved mobility, safety, air quality, and productivity.
2. Why do we need ITS
 we cannot build our way out of congestion
 to reduce accidents and improve safety
 improve economic productivity
 international competition
 reduce driver stress
3. Elements of Intelligent Transportation Systems
(1)
(2)
(3)
(4)
(5)
(6)
Advanced Traffic Management Systems (ATMS)
Advanced Traveler Information Systems (ATIS)
Advanced Vehicle Control Systems (AVCS)
Commercial Vehicle Operations (CVO)
Advanced Public Transportation Systems (APTS)
Advanced Rural Transportation Systems (ARTS)
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coordinated control with other jurisdictions such as police,
emergency, fire crews, etc.
prediction of congestion
provision of timely information to travelers
3.1.1 Expected benefits of ATMS
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reduced travel time by 10-15 percent
reduced fuel use and vehicle emission of pollutants
reduced accidents
3.1.2 Further R&D in ATMS needed:
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to improve traffic detection technologies
to develop interactive traffic signal control
to improve communication technologies
on “real time” traffic models
driver behavioral issues
3.2 Advanced Traveler Information Systems
The objectives of ATIS are to provide to travelers:
 current traffic and road conditions
 navigation information and routing advice
 safety advisory and warning systems
3.2.2 Further R&D in ATIS needed:
• traveler information requirements
• system communication interface
3.3 Commercial Vehicle Operations (CVO)
The objective of CVO is to expedite and improve commodity movement through:
 Automatic Vehicle Identification (AVI)
 Automatic Vehicle Classification (AVC)
 Automatic Vehicle Location (AVL)
 Automatic Cargo Identification
 Weigh-in-motion
3.3.1 Expected Benefits of CVO
• increased productivity -- faster dispatches, efficient routing, and more timely
pickup and deliveries
 reduced time spent at weigh-in stations
 reduced variance in travel time -- important for just in-time
deliveries
 improved hazardous material tracking
 reduced labor cost to administer gov’t truck regulations
 increased toll collection
 “May Day” Capability
4. Barriers and Challenges for ITS
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willingness of the public to pay
public acceptability of in-vehicle advice
liability in case of accident
anti-trust law
standards
human factors -- information workload
institutional cooperation among public & private institutions
privacy issues