Traffic lights cause crashes

Traffic lights are inefficient tools to handle traffic flow and minimise accidents because they encourage drivers to travel too fast and keep dangerously close to the vehicle in front for fear of missing a green light. Kenneth Todd of the Cato Institute says this combination of high speed, tail-gating, diverted attention and sudden stops causes rear end collisions.

In addition, traffic signals cause congestion because they don't moderate the use of the intersection efficiently: often cars sit idly by at a red light only to have no traffic using the green light. Overall, about 40 percent of the vehicle delays in urban areas are due to traffic signal inefficiencies.

Todd's findings suggest that using more roundabouts and more four-way stops will cut down on lost time, taxpayer expense and accidents. According to the Federal Highway Administration (FHWA):

Roundabouts are far safer than traffic signals, cause less delay, and have more vehicle capacity; where used they have reduced serious-injury and fatal accidents by 60 to 90 percent.

Four-way-stop intersections have the best safety record, with half as many accidents as those controlled by two-way stops or signals; serious accidents are extremely rare.

Yield signs have a safety record as good as the stop sign, cause less delay and allow a 50 percent higher rate of traffic flow.

The U.S. motoring public pays an estimated $123 billion annually in lost time, wasted fuel, and other vehicle operation costs, plus billions more for high-tech electronics to moderate America's intersections, says Todd.

Source: Kenneth Todd, Traffic Control: An Exercise in Self-Defeat, Regulation, Fall 2004.

For text http://www.cato.org/pubs/regulation/regv27n3/v27n3-brieflynoted.pdf

For more on Land Issues Transit http://eteam.ncpa.org/policy/Land_Issues/Transit/

FMF Policy Bulletin/ 18 January 2005