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 Illinois, the use of speed enforcement cameras is regulated by state statutes. These cameras are permitted in specific areas, particularly in safety zones which are areas near schools and parks where speed limits are strictly enforced. The Automated Traffic Control Systems in Highway Construction or Maintenance Zones Act also allows the use of speed cameras in construction zones. The law mandates that signs be posted to inform drivers that speed enforcement cameras are in use. Citations issued through these cameras are mailed to the registered owner of the vehicle. The use of these cameras has been a subject of debate, with concerns about privacy and the accuracy of the technology. However, Illinois law provides for the use of these cameras under specified conditions, and they are considered a legal tool for traffic enforcement. Operators of these systems are required to be trained, and the equipment must be regularly calibrated to ensure accuracy.