Traffic engineering (transportation)
Traffic engineering is a branch of
civil engineeringthat uses engineering techniques to achieve the safe and efficient movement of people and goods. It focuses mainly on research and construction of the immobile infrastructure necessary for this movement, such as roads, railwaytracks, bridges, traffic signsand traffic lights.
Increasingly however, instead of building additional infrastructure, dynamic elements are also introduced into road traffic management (they have long been used in rail transport). These use sensors to measure traffic flows and automatic, interconnected guidance systems (for example traffic signs which open a lane in different directions depending on the time of day) to manage traffic, especially in peak hours.
The relationship between lane flow ("Q") (vehicles per hour) maximum speed ("V") (kilometers per hour) and density ("K") (vehicles per kilometer) is "Q" = "KV". Observation on limited access facilities suggests that up to a maximum flow, speed does not decline while density increases, but above a critical threshold, increased density reduces speed, and beyond a further threshold, increased density reduces flow as well.
Therefore, managing traffic density by limiting the rate that vehicles enter the highway during peak periods can keep both speeds and lane flows at bottlenecks high.
Ramp meters, signals on entrance ramps that control the rate at which vehicles are allowed to enter the mainline facility, provide this function (at the expense of increased delay for those waiting at the ramps).
Highway safety engineering is a branch of traffic engineering that deals with reducing the frequency and severity of crashes. It uses physics and vehicle dynamics, as well as road user psychology and human factors engineering, to reduce the influence of factors that contribute to crashes.
Traffic engineering is closely associated with other disciplines:
*Human factors engineering
Bus rapid transit
Hierarchy of roads
Intelligent Transportation System
Road traffic control
* Homburger, Kell and Perkins, "Fundamentals of Traffic Engineering, 13th Edition", Institute of Transportation Studies, University of California (Berkeley [http://www.its.berkeley.edu/publications/] ), 1992.
* Das, Shantanu and Levinson, D. (2004) A Queuing and Statistical Analysis of Freeway Bottleneck Formation. "ASCE Journal of Transportation Engineering" Vol. 130, No. 6, November/December 2004, pp. 787-795
Wikimedia Foundation. 2010.
Look at other dictionaries:
Traffic engineering — can mean: * traffic engineering (transportation), a branch of civil engineering * teletraffic engineering, a field of statistical techniques used in telecommunications … Wikipedia
Traffic psychology — is a young, expanding field in psychology. Whereas traffic psychology is primarily related to the study of the behaviour of road users and the psychological processes underlying that behaviour (Rothengatter, 1997, 223) as well as to the… … Wikipedia
Traffic congestion — Traffic jam redirects here. For other uses, see Traffic jam (disambiguation). Traffic congestion on Marginal Pinheiros, near downtown São Paulo. According to Time magazine, São Paulo has the world s worst traffic jams.[1 … Wikipedia
Traffic calming — is a set of strategies used by urban planners and traffic engineers which aim to slow down or reduce traffic, thereby improving safety for pedestrians and bicyclists as well as improving the environment for residents. Calming measures are common… … Wikipedia
Traffic Design Group — or TDG is a consultancy in New Zealand. The largest [http://www.futureintech.org.nz/AprilNewsletter.pdf Enews April 2004] (Futureintech, Government funded initiative of IPENZ)] specialist traffic engineering and transport planning consultancy of… … Wikipedia
Traffic Control — ➡ law enforcement * * * Introduction supervision of the movement of people, goods, or vehicles to ensure efficiency and safety. Traffic is the movement of people and goods from one location to another. The movement typically occurs… … Universalium
Transportation in Dresden — Dresden is major German city and capital of Saxony. It is a road, train and air transport hub in eastern Germany. Local and commuter transport services grant accessibility in the Dresden agglomeration. The city has a dense network of tram and bus … Wikipedia
Transportation Library, UC Berkeley — The Harmer E. Davis Transportation Library mdash;also known as the Institute of Transportation Studies Library (ITSL), the Berkeley Transportation Library, or simply as the Transportation Library mdash; is a library at the University of… … Wikipedia
Traffic Operations Practitioner Specialist — A Traffic Operations Practitioner Specialist (TOPS) is a certification sponsored by the Transportation Professional Certification Board, Inc., and promulgated by the Institute of Transportation Engineers. Prior to taking the required exam, an… … Wikipedia
Traffic Signal Operations Specialist — A Traffic Signal Operations Specialist (TSOS) is a certification sponsored by the Transportation Professional Certification Board, Inc., and promulgated by the Institute of Transportation Engineers. Prior to taking the required exam, an… … Wikipedia