Traffic on roads may consist of pedestrians, ridden or herded animals, vehicles, streetcars and other conveyances, either singly or together, while using the public way for purposes of travel. Traffic laws are the laws which govern traffic and regulate vehicles, while rules of the road are both the laws and the informal rules that may have developed over time to facilitate the orderly and timely flow of traffic.
Organized traffic generally has well-established priorities, lanes, right-of-way, and traffic control at intersections.
Traffic is formally organized in many jurisdictions, with marked lanes, junctions, intersections, interchanges, traffic signals, or signs. Traffic is often classified by type: heavy motor vehicle (e.g., car, truck); other vehicle (e.g., moped, bicycle); and pedestrian. Different classes may share speed limits and easement, or may be segregated. Some jurisdictions may have very detailed and complex rules of the road while others rely more on drivers' common sense and willingness to cooperate.
Organization typically produces a better combination of travel safety and efficiency. Events which disrupt the flow and may cause traffic to degenerate into a disorganized mess include: road construction, collisions and debris in the roadway. On particularly busy freeways, a minor disruption may persist in a phenomenon known as traffic waves. A complete breakdown of organization may result in traffic congestion and gridlock. Simulations of organized traffic frequently involve queuing theory, stochastic processes and equations of mathematical physics applied to traffic flow.
Traffic in English is taken from the Arabic word taraffaqa, which means to walk along slowly together.
Famous quotes containing the word traffic:
“There was a girl who was running the traffic desk, and there was a woman who was on the overnight for radio as a producer, and my desk assistant was a woman. So when the world came to an end, we took over.”
—Marya McLaughlin, U.S. television newswoman. As quoted in Women in Television News, ch. 3, by Judith S. Gelfman (1976)
“To treat a big subject in the intensely summarized fashion demanded by an evenings traffic of the stage when the evening, freely clipped at each end, is reduced to two hours and a half, is a feat of which the difficulty looms large.”
—Henry James (18431916)
“Theres something about the dead silence of an office building at night. Not quite real. The traffic down below is something that didnt have anything to do with me.”
—John Paxton (19111985)