The LTI 20.20 Ultralyte 1000 mobile speed camera is manufactured by Laser Technology Inc in the US and distributed by Tele-Traffic UK Ltd in the UK. All LTI cameras used by the SEU are supplied by Tele-Traffic who also performs the yearly calibration testing, any required maintenance and operator training.
The LTI 20.20 Ultralye 1000 and the Lastec Concept 2 and Lastec Ranger video recording systems have Home Office Type Approval (HOTA) for use in detecting and recording evidence of speeding offences. A copy of this approval can be viewed here: LTI 20.20 Ultralye 1000 HOTA
The LTI 20.20 Ultralyte 1000 is designed to accurately detect the speed of vehicles at up to 1km away. It uses reflected pulses of laser light to measure the changing distance between the camera and the vehicle from which it can calculate its speed. Speed readings are obtained in 0.3 seconds to an accuracy of within +/- 1mph.
The SEU deploys LTI cameras using vans and motorbikes. Van based LTI cameras are mounted in the van and used in conjunction with the Concept 2 video recording system. Motorbike based LTI cameras are deployed at the roadside on a collapsible tripod and used with a Ranger recording system. The cameras are never operated handheld. Both recording systems capture a video of the full speed check session and associated data which is saved to a Compact Flash card for processing at the SEU office.
LTI cameras are used as a secondary check to confirm the expert opinion of a Camera Enforcement Officer (CEO) that a vehicle is exceeding the speed limit and obtain an accurate speed reading.
To do this the CEO aims the camera at a flat vertical surface on the vehicle, such as the licence plate, and then presses the trigger. They only have to track the vehicle for 0.3 seconds to obtain a speed reading. The camera takes a series of distance checks during that time which it analyses to ensure they are consistent. If the readings are consistent the speed check result is displayed on screen. Otherwise an error message is displayed instead and the CEO has to pull the trigger again to perform another speed check.
The LTI cameras are tested annually by their UK supplier, Tele-Traffic, who issue a Calibration Certificate to confirm that the camera is working correctly.
The CEOs carry out a distance check over a pre-measured distance with the camera at the start and end of each working day.
The LTI cameras automatically carry out self diagnostic checks when they are switched on and will not operate if they fail.
At the start and end of each speed check session the CEO performs a speed check on a fixed object to ensure a reading of 0mph is registered. They also check that the crosshairs on the video are correctly aligned with the LTI camera's laser beams.