What is a “speed retarder”?
- Correct answer: An electric or hydraulic mechanism, independent of the vehicle’s braking system, which decelerates the vehicle when operated.
- An electronic system which automatically operates the brakes while driving on a steep decent, thus preventing brake overheating and brake loss.
- A system installed in the vehicle that assists in emergency braking and stops the vehicle on the spot.
- An electric mechanism installed in the braking system that shuts-off the engine and helps the vehicle to maintain constant speed on all roads.
Why this is the answer
The correct answer in the official bank: An electric or hydraulic mechanism, independent of the vehicle’s braking system, which decelerates the vehicle when operated.
A speed retarder is an electric or hydraulic device that works separately from the service brakes and slows a heavy vehicle when the driver switches it on. It is mainly used on long descents, taking load off the ordinary brakes so they do not overheat and lose effectiveness. It does not apply the brakes itself, stop the vehicle on the spot or shut off the engine.