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

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 heavier-

than-air machine in 1903

History of Transportation

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

The interstate highway system was initiated in 1950

The first commercial jet appeared in 1958

Air transportation

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 well-developed 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

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.

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.

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

Careers in Transportation

What transportation engineers do

Transportation Topics

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 usersThe 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

intersectionSee Figure 3-2 (McShane&Roess) for 85th-percentile perception-

reaction timeAASHTO 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. Lengthii. Widthiii. Heightiv. Wheelbasev. Weightvi. Acceleration/decelerationvii. Speedviii. 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 speedDesign 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 distanceThere are two types of sight distance used in designing highways:

a. Stopping sight distance

b. Passing sight distance

Stopping sight distanceStopping 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 distancePassing 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)  1960    2000   

Highwaya 3,545,693 3,936,229

Class I railb,c 207,334 99,250

Amtrakc N 23,000

Transitd

  Commuter railc N U

  Heavy rail N U

  Light rail N U

Navigable channelse 25,000 26,000

Oil pipelinef 190,944 U

Gas pipelineg 630,950 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

Private use, total 10,347 13,990

% with lighted runways 15.2 7.3

% with paved runways 13.3 32.0

TOTAL airports 15,161 19,306

Certificatedb, total 730 635

Civil N 562

Civil-Military N 73

General aviation, total 14,431 18,760

Table 1-4: Public Road and Street Mileage in the United States by Type of Surfacea (Millions of miles)

  1960 2000 

TOTAL paved and unpaved 3.546 3.950

Pavedb

  Low and intermediate type 0.672 dN

  High-type 0.558 dN

Paved total 1.230 2.504

Unpavedc total 2.315 1.446

1990 2000 TOTAL automobiles and trucks in fleets 15,196

Number of automobiles in fleets of 25 or 

more (10 or more cars for 1999 and 2000)a

Businessb 2,889 2,950Governmentc 538 883Utilities 551 317Police 249 306Taxi (includes vans) 141 136  Rental (includes vans and SUVs) 990 1,581

Number of automobiles in fleets of 4 to 24

(4 to 9 cars for 1999 and 2000)a U 1,173Total automobiles in fleets 7,346

Number of trucks in fleets of 25 or 

more (10 or more trucks for 1999 and 2000)a

Businessd U 3,026Governmentc U 2,408Utilities U 498Other (police, taxi, etc.) U 8Rental trucks (not vans and SUVs) U 248

Number of trucks in fleets of 4 to 24

(4 to 9 trucks for 1999 and 2000)a U 1,662Total trucks in fleets 7,850

Table 1-12: U.S. Automobile and Truck Fleets by Use (Thousands)

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

Imports

Japan 313 863

Germany 750 517

Other 217 637

  Total 1,280 2,016

Signal Timing1. DefinitionsA signal cycle is one complete rotation through all of the indications providedThe 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 all-red 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:

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 way to different traffic streams at different times. See Figure 8.3.

PHFVolume during peak hour

4 x flow during peak 15 min within peak hour

3. Yellow IntervalThe 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. Definition1. DefinitionIntelligent 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 ITS2. 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 Systems3. Elements of Intelligent Transportation Systems(1) Advanced Traffic Management Systems (ATMS)(2) Advanced Traveler Information Systems (ATIS)(3) Advanced Vehicle Control Systems (AVCS)(4) Commercial Vehicle Operations (CVO)(5) Advanced Public Transportation Systems (APTS)(6) Advanced Rural Transportation Systems (ARTS)

3.1 Advanced Traffic Management Systems3.1 Advanced Traffic Management SystemsThe objective of ATMS is to monitor, control, and manage traffic on freeways, arterials, corridors, etc. through: real time and area wide surveillance fast detection, verification, response & clearance of incidents

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 ATMS3.1.1 Expected benefits of ATMS 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:3.1.2 Further R&D in ATMS needed:• 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 Systems3.2 Advanced Traveler Information SystemsThe objectives of ATIS are to provide to travelers: current traffic and road conditions navigation information and routing advice safety advisory and warning systems yellow pages functions

3.2.1 Expected benefits of ATIS3.2.1 Expected benefits of ATIS reduced travel time by 10 to 15 percent reduced fuel use and emissions reduced accidents improved commercial productivity improved safety

3.2.2 Further R&D in ATIS needed:3.2.2 Further R&D in ATIS needed:• traveler information requirements• system communication interface

3.3 Commercial Vehicle Operations (CVO)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 CVO3.3.1 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

3.4 Advanced Vehicle Control Systems (AVCS)3.4 Advanced Vehicle Control Systems (AVCS)The objective of AVCS is to provide drivers with warning, assistance, and control of their vehicles through: lateral and longitudinal control e.g. rear proximity warning system and intelligent cruise control vision enhancement devices (infrared night vision equipment) heads-up display

“May Day” Capability

4. Barriers and Challenges for ITS4. Barriers and Challenges for ITS 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