The T3L from PSY Systems is a visible optical speed indicating system that contributes to road safety by allowing motorists to understand the speed-change intentions of the vehicle in front. It consists of an ABB CPU operating in conjunction with the conventional vehicle braking indication systems.

 
 In most braking systems, when the vehicle’s brake pedal is depressed the rear red brake lights illuminate. Vehicles fitted with additional rear window or boot spoiler brake indicating systems only mimic the same rear red brake lights. A typical unindicated speed change scenario would be a driver maintaining a constant pressure on the accelerator pedal while travelling along an inclined road and actually losing speed. Without T3L technology there is no indication to the following motorist of the change.

Designed for both OEM and retrofit markets, the T3L unit has a display indicator situated at the rear of the vehicle, either in the rear window or embedded in the boot or roof spoiler. It also has a standard vehicle speed sensor. Both display and sensor plug into the ABB CPU unit with speed changes represented by various arrangements of coloured lights on the rear of the vehicle.

In the bar strip system the light strips vary in length to indicate speed change rates. If the red LED strip is on and varying in length, the vehicle is decelerating; if the amber LED strip is on and varying in length, the vehicle in front is maintaining speed and if the green LED strip is on and varying in length, the vehicle in front is accelerating. When the wave strip system is used, the light strips vary in shape to indicate the three scenarios and in the tri-state system, fixed shape light strips change colour.

For the retrofit market a standalone system has been designed. A speed sensor is installed to sense any part of the vehicle’s rotational mechanism, this being directly proportional to the velocity. Alternatively a speed signal can be fed from the vehicle’s electronic system. This is fed into the T3L unit’s ABB CPU to analyse speed differences, the result being transferred to the display unit, indicating speed changes via colour LEDs or alphanumeric displays.

For the OEM market an integrated speed sensor is installed. T3L algorithms are programmed into the vehicle’s computer. The speed signal is fed into the vehicle’s computer to analyse speed differences. The result is transferred to either the T3L display unit or the vehicle’s rear lighting system.

Readers wanting more detailed system specifications can visithttp://instrumentation.co.za/papers/C15426A.doc