In which of the following cases is the use of a cruise control most justified?
Show the correct answer
Correct answer
C. While driving for a long time at constant speed.
Explanation
The question is about the situation in which using cruise control is most justified. It is driving for a long time at a constant speed - the answer is C.
The Road Traffic Act requires you to adjust your speed to the traffic conditions and to drive at a speed that allows you to keep control of the vehicle. Cruise control keeps the set speed without you pressing the accelerator, so it works well where the speed does not change for a long time - on a motorway or an expressway with light traffic. It helps you save fuel and makes your right leg less tired. In the mountains (answer A), ordinary cruise control does not brake when going downhill, so the lorry speeds up above the set speed, and when going uphill cruise control makes the engine labour in too high a gear; and in the city (answer B) you keep slowing down, stopping and moving off, so cruise control only gets in the way. On a wet or slippery surface it is better to switch it off.
Legal basis: Art. 19 para. 1 of the Road Traffic Act (Prawo o ruchu drogowym)