Introduction CE 331 Transportation Engineering Fall 2013 Dr

Introduction CE 331 Transportation Engineering Fall 2013 Dr. Reg Souleyrette

Transportation Systems ¢ Highway Auto, truck, bus, bicycle Rail ¢ Air ¢ Water ¢ Continuous flow system ¢ Pipeline, belt

Issues and Challenges ¢ Traffic congestion Why? Demand > supply l Usual response: more capacity l • Limitations: funding, environmental impact l Alternatives: • ITS initiatives: ATIS • Traffic control: signal coordination, ramp metering • Planning: land use, congestion pricing

Issues and Challenges (cont’d) ¢ Traffic safety Accidents (Crashes) are of concern for all modes of transportation l Most visible in commercial air transportation or rail with mass casualties l Auto crash fatalities are decreasing l Commercial aviation fatalities are relatively low and quite variable l

Issues and Challenges (continued) ¢ Equality of access With auto being the dominant travel mode: l Low income people, elderly, and handicapped may be underserved

Issues and Challenges (cont’d) ¢ Environmental impact l System level impact: • Air quality • energy and land consumption l Site specific impact: • Noise • Water quality • Displacement of residents and business

Issues and Challenges (cont’d) ¢ New technology l How to incorporate? • Electric cars, natural gas, fuel cell l Intelligent transportation system (ITS) • • Improve safety Reduce congestion Improve mobility and accessibility Improve economic productivity

What do transportation engineers do?

Course Outline ¢ Intersection and signals Unsignalized intersection l Signal timing design l ¢ Geometric design Sight distance l Horizontal and vertical alignment l

Course Outline (cont’d) ¢ Operations analysis Traffic flow fundamentals l Traffic studies l Capacity analysis l ¢ Transportation planning Four-step procedure for demand forecasting l Other modes l

Characteristics of Driver, Vehicle, and Road

Characteristics of Drivers’ skills and perceptual abilities vary with person, physical condition ¢ Perception-Reaction Process ¢ l Four sub-processes: • Perception (mostly visual) • Identification (understand the stimulus) • Emotion (decide what action to take in response) • Reaction (executing the action)

Characteristics of Driver (cont’d) ¢ Perception-Reaction Process (cont’d) Total time for the process is called perception-reaction (P-R) time l P-R time varies from 0. 5 to 7. 0 sec l AASHTO recommendation: l P-R time = 2. 5 sec ** this covers 90% of drivers under most highway conditions l Very important when determining stopping sight distance

Characteristics of Vehicle ¢ Physical dimensions Length – parking space length l Width – lane width l Height – vertical clearance l Weight – structural design of surface, guideway, and bridge ¢ Acceleration/deceleration characteristics – maximum grade ¢

Characteristics of Road Min. radius of horizontal curve ¢ Max. rate of superelevation ¢ Max. grade ¢ Min. grade and cross-slope ¢ Min. length of vertical curve ¢ Other ¢