Lidar (light detection and ranging) has a wide range of applications; one use is in traffic enforcement and in particular speed limit enforcement, gradually replacing radar after year 2000. Current devices are designed to automate the entire process of speed detection, vehicle identification, driver identification and evidentiary documentation.
Lidar has advantages over radar. Radar has wide signal beam divergence so that an individual vehicle cannot be targeted, requiring significant operator skill, training and certification in order to visually estimate speed so as to locate an offender in a traffic stream, and offenders may use the defense that some other vehicle was offending. Radar will register the speed of any object in its field, for example a tree swaying or an airplane passing overhead.
Lidar has a narrow beam, and easily targets an individual vehicle, thereby eliminating the need for visual estimation, and records an image of the license plate at the same instant as recording the speed violation. Speed estimation takes less than half a second which together with the narrow, targeted beam results in offending vehicles having little warning even when using an evasion device. Lidar can also measure the distance between vehicles to detect tailgating infringements.
State-of-the-art modern lidar devices, utilized by Underwriting Resources’ Traffic Surveillance Initiative, record each passing vehicle (up to 2,000 per day per device), registers its speed with an accuracy of +/-1.2 mph from a distance of nearly 2,000 feet away and license plate number from a distance of up to 500 feet away or over 1½ football fields, takes a full-color image and video, detects violation events, adds a time stamp and a location stamp and creates an anti-fraud, anti-corruption, no-tamper designed data package which it stores and forwards to a central database. Unlike a handheld speed gun or a typical police speed control device which needs operating personnel, our lidar technology of choice is fully self-operated. Once set up on location, it uses automatic license plate recognition technology to identify vehicles, takes still images and video, deploys event recognition to record their behaviour in traffic, uses its integral GPS to add location data and does all this without human intervention.