Red Light Cameras and How They Work

In 2019, AAA reported that fatalities caused by drivers running red lights hit a 10-year high. In fact, more than two people a day are killed by drivers blowing through red lights. We can only assume that the number of non-fatal injuries and damaged property resulting from the same reckless driving behavior is even higher.

In an attempt to curb this dangerous behavior, many states have implemented the use of red light cameras. If you’ve ever received a letter in the mail with a picture of your car and a ticket, you’ve encountered these devices already.

Depending on where you live, the fine for running a red light can run as high as $1,000. Some states will also add points to your driving record which can come with serious consequences down the road.

Read on to find out more about how a red light camera program works and why it’s important that you follow traffic laws at all times.

How Do Red Light Cameras Work?

The objective of a red light camera is to catch drivers in the act of running a red light. This cuts down on the need for law enforcement officers on every corner while still discouraging people from driving recklessly. The overall objective is to lower accidents and fatalities caused by red light running.

In order for red light cameras to capture suitable evidence, they must get a clear photo of the car’s license plate and, in some states, the driver. How does this work?

There are three main components that work together to capture these photos: cameras, triggers, and computers. Read more about how they work.


The first component is a camera, although in some intersections there may be multiple cameras. They are usually posted above or near the stoplights at four-way intersections and face inward. A system with multiple cameras can capture pictures of the offending car from several angles to ensure a clear shot.

Most of these cameras record images digitally. Some older red light cameras may still rely on film, although most cities have moved away from film red light cameras. Cameras that use film must be emptied periodically, meaning that violations aren’t recorded right away.


Red light cameras work in connection with triggers that are positioned just past the stop line. They are designed to detect vehicle movement when cars should be stopped at a red light.

A common trigger used in this system is an induction loop trigger. Induction loops are electrical wires that are planted just below the surface of the asphalt. The wire is attached to an electrical source that creates a magnetic field that runs through the wires.

The electrical meter monitors the inductance running through the magnetic field. When it is altered, it sends a signal to the meter that a car has passed through the magnetic field.

Other triggers rely on radars, lasers, or air-tube sensors. However, these systems tend to be less reliable than the induction loop trigger.

Note that the triggers ignore disruptions that occur due to stationary vehicles. In other words, if you stop on the trigger, you will not set off the camera. They also should ignore your car if you were already in the intersection when the light initially turned from yellow to red.


The cameras and triggers are useless without a computer. The computer component in a red light camera system knows to ignore the triggers when the light is green or yellow. The computer system is only “on” when the light is red.

If the computer system is on and the triggers are activated, the computer alerts the cameras to snap some photos. It informs the cameras to take a photo as the car enters the intersection, pause, and take another that shows that the car proceeded through the intersection in spite of the red light.

Do All States Use Red Light Cameras?

The short answer is no, not all states use red light cameras. There have been some issues with these systems in the past, leading some states to use red light cameras only under certain conditions or do away with them all together. In other words, red light cameras are used on a state-by-state basis.

What Happens if You’re Caught on a Red Light Camera?

Once again, the answer to this question depends on the state where you live. What remains the same is that a notice of violation letter will be mailed to the address associated with the driver’s license plate number (registered owner or vehicle owner).

This letter will include not only the photo of the violation and a fine but also a date. You must pay your fine by this date or request a hearing to try to dispute the ticket.

It is possible that you will also accrue points on your driving record. These points indicate that you have had issues with driving laws in the past. In some states, if you accrue a certain amount, you are at risk of having your driver’s license revoked altogether.

Most insurance companies will increase your rates when you accrue points on your driving record. This is because they consider past violations a sign that you are a bigger liability.

How to Reduce Your Insurance Rates After Running a Red Light

One place to turn after receiving a ticket for running a red light is defensive driving school. Only a few hours interacting with an online course can reduce your insurance rates by up to 10 percent.

These courses are designed to work on nearly any device and you can always stop and pick up where you left off, making it easier than ever to receive a defensive driving certificate. You can even try a free demo before you commit to the full course.

Defensive driving courses cover all sorts of topics that will refresh your memory on the rules of the road. On top of that, these courses will update you on any laws that have changed since you took driver’s education classes and provide you with tips to avoid accidents.

When you show your insurance company that you’ve completed a defensive driving program, it gives them more reason to trust that you are driving safer and smarter than ever before. It’s a sign that you take your traffic violation seriously and want to ensure both your safety and everyone else’s.

The Problem with Running Red Lights

When your light is red, that means that someone else has the right of way. In some cases, that may be the drivers who are coming from your right or left. In others, it could be drivers across from you who have a left-turn light or pedestrians.

In other words, your light is red because someone else’s is green. The drivers, bikers, and pedestrians around you are trusting that you will follow the rules and let them cross safely.

It is not just the red light you need to watch. While turning right at a red light is acceptable in some scenarios, it is not always legal.

Before you turn right on red, check to make sure that there are no signs near the stoplight informing you not to do so. Some “No Right Turn on Red” signs are unconditional while others may indicate a certain time frame in which this maneuver is illegal.

If it is legal to turn right on red, make sure that you have a clear path to do so. You are still expected to yield to other drivers or pedestrians who have the right of way.

How to Avoid Running a Red Light

The best way to avoid running a red light is to stay alert. As you approach an intersection, keep an eye on the traffic light. If it turns yellow before you reach the intersection, begin to slow down and stop safely.

Maintain a steady speed if the light is green when you’re several yards away. Increasing your speed to make the light is dangerous. If the light turns red in that time, your options are to fly through it or slam on your breaks, both of which could cause an accident.

Even if you’re allowed to make a right turn on red, make sure you come to a complete stop first. If an accident were to occur while making the right turn, it would be your violation and your insurance covering the damage.

Lower Your Insurance Rates After Running a Red Light

If you’ve been ticketed for red light violations and you need to refresh your memory on rules of the road, consider taking a defensive driving course. You can feel more confident behind the wheel and lower your insurance rates.

To start your course, select your state and follow the prompts on the screen. Good luck and happy defensive driving!