Question 1396 in the bank

When is it obligatory to operate the speed retarder while driving downhill?

  1. Only when the slope rate is indicated in the “steep descent” sign.
  2. In every downhill road section.
  3. When the slope rate of the descent exceeds 6% and the length of the descent exceeds one kilometer.
  4. Correct answer: When a “dangerous descent” sign is posted.

Why this is the answer

The correct answer in the official bank: When a “dangerous descent” sign is posted.

In a heavy vehicle fitted with a speed retarder, you must use it whenever a dangerous descent sign is posted, whether or not the sign shows the slope percentage. The retarder slows the vehicle without overloading the service brakes, which could overheat and lose effectiveness on a long descent. The duty does not apply to every downhill, nor does it depend on a specific slope or length.

Topic: Rules and regulations. The bank marks it for these classes: Light truck (C1), Heavy truck (C), Bus (D).