By John McCurley , Attorney · University of San Francisco School of Law
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 actually 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 catches you running a light. Hopefully, this information will also be useful in avoiding red-light camera tickets.
Knowing a little about how red-light cameras work and where they're located can go a long way in avoiding camera tickets.
Most states that permit red light cameras require that signs be posted informing drivers if cameras are in use at an intersection. In jurisdictions that have red-light cameras, it's common for only the busiest intersections to be equipped with cameras. Also, the cameras themselves are usually fairly conspicuous: Typically, you'll see four large camera boxes positioned at the corners of the intersection.
However, the easiest way to find out where red-light cameras are at is to go to the internet. Generally, a quick internet search can show you where the red-light cameras in your area are located.
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.
Basically, if you go past the limit line while the light is red, there's a pretty good chance of triggering the red-light camera. Oftentimes, you'll also see a camera flash when a red-light camera takes a photo.
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. Generally, the person checking the footage has the last word on whether to issue a citation.
Red-light camera tickets come in the mail. 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:
Grace periods for new camera sites. 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.
A word on red-light camera defenses. Although state laws differ, many states have specific defenses for vehicle owners who can prove they were not driving the vehicle when the violation occurred. For example, a registered owner might be able to contest a red-light camera ticket by filing a declaration with the court stating that he or she was not driving the vehicle when the violation occurred.