Lots of states allow automated cameras at intersections to catch red-light violators. But it's typically up to each city or municipality within the state to decide whether to use red-light cameras. If you have red light cameras in your area, you might wonder how you would know if you got a ticket.
This article covers the basics of how red light cameras work and how you'll find out if one of these cameras photographs you running a light.
Knowing which intersections have cameras. Most states that permit red light cameras require that signs be posted informing drivers if cameras are in use at an intersection. Also, the cameras themselves are usually fairly conspicuous: Typically, you'll see four large camera boxes positioned at the corners of the intersection.
How cameras catch violators. Automated intersection cameras generally involve three components working in sync: the signal (traffic light), cameras, and pavement sensors. Each red light camera is aimed at traffic going in one direction. Sensors in the pavement (called "in-road" or "loop" sensors) estimate the speed of vehicles as they approach the limit line or crosswalk of the intersection. If the light is red and these sensors estimate a vehicle is going too fast to stop, the camera is triggered. The camera usually takes still shots and a video of the driver going through the light.
Red light cameras are fairly accurate but not perfect. So, even if you see the flash of the camera going off, you might not get a ticket. Before a ticket goes out, someone (usually a technician or officer) will review what the camera captured. The person checking the footage has the last word on whether to issue a citation.
Red light camera tickets are typically mailed to the registered owner of the vehicle. Most states require violation notices to be mailed within a certain number of days of when the violation occurred. So, it might take anywhere from about 30 to 60 days to get the ticket in the mail. Generally, the violation notice will include:
Some states have a 30-day grace period that applies when red light cameras are first installed. During the grace period, no tickets are issued but warning notices are sent to drivers who are photographed running the signal.