When you are driving a truck down a steep descent:
- Drive down on high gear and stop the vehicle every few kilometers.
- Drive down on neutral gear and use the brakes according to need.
- Correct answer: Drive in an appropriate low gear and make sure that the vehicle’s special deceleration mechanisms are operating.
- The use of gears to brake the vehicle is of no significance.
Why this is the answer
The correct answer in the official bank: Drive in an appropriate low gear and make sure that the vehicle’s special deceleration mechanisms are operating.
On a steep descent a heavy truck gains speed quickly, and relying only on the service brakes overheats them until they lose effectiveness. An appropriate low gear uses engine braking, while special deceleration mechanisms such as a retarder or exhaust brake help hold a steady speed. Coasting in neutral removes engine braking entirely and is very dangerous.