Cameras placed at traffic-light intersections discourage red-light running, and reduced injury-causing car accidents by nearly one-third in one California town, according to research by the Insurance Institute for Highway Safety (IIHS) released April 26, 2001.

Introduced in Oxnard, Calif., in 1997, enforcement cameras are credited with reducing injury crashes in that town by 29 percent, IIHS says. The cameras photograph red-light runners in the act, and those drivers are later sent traffic tickets in the mail. Front-into-side collisions, the most common resulting from red-light running, were reduced 32 percent in Oxnard, and front-into-side collisions resulting in injuries were reduced 68 percent.

The IIHS also found that in Oxnard, where 11 of 125 intersections were equipped with cameras, drivers ran fewer red lights even at intersections without the cameras, showing the cameras' "strong deterrent value" and "ability to change driver behavior," according to the IIHS.

Previous research showed that cameras reduce the incidence of red-light running by about 40 percent, but this IIHS study is the first to show that cameras reduce crashes. The IIHS says the Oxnard study should convince state legislatures to overturn their ban on camera use as a basis for ticketing motorists. Currently, 10 states allow camera enforcement of traffic laws: Arizona, California, Colorado, Delaware, Hawaii, Maryland, New York, North Carolina, Oregon, and Virginia.

Privacy advocates criticize traffic cameras, calling them unconstitutional and a violation of motorists' privacy. But the IIHS says that the benefits of traffic cameras to the general public should encourage their widespread use, citing polls that show about 80 percent of motorists favoring camera use in cities with and without the cameras.