Running a red light is illegal in all states and a ticket or citation for the infraction or offense may lead to a significant fine, demerit points on a driver’s license or driving record, and increased insurance premiums (upon conviction, guilty plea, or plea of no contest).

Due to limited resources many states use automated red-light cameras—also known as photo enforcement—to take a digital photograph of a vehicle (and its license plate) that violates the red light or traffic signal by entering the intersection and failing to stop after the light has turned red. The use of red-light cameras to issue traffic tickets or citations (mailed to the driver) has been controversial, with claims that it violates Constitutional rights.

Laws vary from state to state and in some states red-light cameras are a permitted enforcement tool; in some states they are prohibited; and in some states they are prohibited unless permitted by a local ordinance (city or town).

In California, running a red light is considered a traffic violation and is illegal under California Vehicle Code 21453. Violators may receive a ticket, which can result in a fine, points on their driving record, and potentially higher insurance rates. California permits the use of automated red-light cameras for traffic enforcement. These cameras capture images of vehicles that enter an intersection after the traffic light has turned red. The registered owner of the vehicle typically receives a citation in the mail. The use of red-light cameras has been subject to legal challenges, but the California Supreme Court has upheld their use, provided that certain procedural safeguards are met, such as proper signage notifying drivers of the camera enforcement and a review of the photographic evidence by a law enforcement official before a citation is issued. Local jurisdictions within California have the authority to implement and regulate the use of red-light cameras.