Georgia Commercial Driver License Practice Test

Which action helps maintain control over your truck during a steep descent?

1. Using engine braking methods

2. Accelerating downhill

3. Shifting to a lower gear

4. Turning off the truck engine

The correct answer is: Using engine braking methods

Using engine braking methods is an effective way to maintain control over your truck during a steep descent because it utilizes the vehicle's engine to help slow down the truck without solely relying on the brake system. When you engage in engine braking, you downshift to a lower gear, which causes the engine to slow the vehicle down by creating a resistance to the motion. This method reduces the risk of overheating the brakes, which can lead to brake failure—especially dangerous on steep inclines. In contrast, accelerating downhill increases your speed and can lead to loss of control. Shifting to a lower gear also helps with control, but if considered alone without the focus on engine braking techniques, it may not fully utilize the vehicle's capabilities to slow down effectively. Turning off the truck engine is not a viable option, as it eliminates power steering and power brakes, making the vehicle much harder to control. Therefore, engine braking is a preferred and safe technique during a steep descent.