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 Wisconsin, running a red light is considered a traffic violation and is illegal under state law. Violators can receive a ticket or citation, which may result in fines, demerit points on their driving record, and potentially higher insurance rates. Wisconsin Statutes section 346.37 outlines the requirements for drivers approaching traffic signals, including red lights. Regarding automated red-light cameras, Wisconsin is among the states that do not permit the use of these devices for traffic enforcement. The state law specifically prohibits the use of automated traffic enforcement cameras to detect or prosecute violations related to traffic signals. This means that in Wisconsin, all traffic citations for running a red light must be issued by a law enforcement officer who has witnessed the violation, rather than through photographic evidence from red-light cameras.