Due to limited resources many states use speed enforcement cameras—also known as photo or video enforcement—to take a digital photograph or video of a vehicle (and its license plate) that violates the speed limit. The use of speed enforcement cameras to issue speeding 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 speed enforcement 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).

To measure the speed of a moving vehicle and issue speeding tickets by photo enforcement, police departments generally use photo or video radar that relies on radio signals and the Doppler Effect or photo and video LIDAR (Light Detection and Ranging) technology that relies on lasers rather than radio waves. These devices require training on their proper use and regular calibration to be accurate.

In Arizona, the use of speed enforcement cameras, also known as photo radar, is permitted under state law. These systems are commonly used in various cities and towns to capture digital photographs or videos of vehicles exceeding the speed limit. The evidence collected by these cameras is then used to issue citations to the registered owners of the vehicles. Arizona law requires that signs be posted to inform drivers that photo enforcement is being used in the area. The citations typically include a fine and may result in points being added to the driver's license. It is important to note that the use of these systems has been subject to legal challenges, but they have been upheld by Arizona courts. Operators of photo radar equipment are required to ensure the devices are properly calibrated and maintained, and personnel must be adequately trained in their use to ensure the accuracy and reliability of speed measurements.