How Do Traffic Cameras Work?
While traffic cameras seem simple enough – a driver runs a red light and a camera snaps a picture of the license plate – the technology used is actually quite complex.
Red-light cameras are composed of four main parts:
- A series of sensors or triggers
- Multiple cameras
- A network of computers
- A human review
The purpose of the traffic camera trigger is to sense the movement of a car as it runs a red light. Placed somewhere at a particular point in the road, these sensors use electrical impulses to create a magnetic field. When a car enters this field, it causes a disturbance.
The computer takes over at this point. Using a series of mathematical formulas, it calculates the position of the vehicle traveling through the magnetic field. The computer is also able to sense the rate at which the vehicle is moving. If it is determined that a traffic violation is about to occur, the computer sends a message to the red-light camera, instructing it to begin snapping pictures.
At this point, the traffic camera will record at least two photographs. The first one being a picture of the car as it enters the intersection when the light is red. The second one is a picture of the car exiting the intersection when the light is still red.
Finally, before the ticket can be issued, each alleged violation is reviewed by a third party. Many states and cities employ an outside company to review and handle these alleged traffic camera violations. If the citation proves to be valid, a ticket will be issued within one to two months.
There you have it; you can officially answer the question “How Do Traffic Cameras Work?