Red Seal Truck and Transport Mechanic Practice Exam

What safety feature helps prevent a truck from rolling backward on a hill?

1. Anti-lock braking system

2. Hill start assist system

3. Traction control system

4. Electronic stability control

The correct answer is: Hill start assist system

The hill start assist system is specifically designed to help prevent a truck from rolling backward when starting on an incline. This safety feature automatically holds the brakes for a short period of time after the driver releases the brake pedal. This allows the driver to transition smoothly from the brake to the accelerator without the risk of rolling back, providing added confidence and control during ascents. In contrast, the anti-lock braking system works to prevent the wheels from locking up during braking, which helps maintain control in emergency braking situations but does not specifically address the issue of rolling backward on inclines. The traction control system primarily focuses on preventing wheel spin during acceleration on slippery surfaces, and while it contributes to overall vehicle stability, it does not directly aid in preventing rollback on hills. Electronic stability control helps maintain vehicle control during slippery conditions but is not designed to assist with starting on a slope. These features collectively enhance vehicle safety, but the hill start assist system is the most relevant for preventing rollback on inclines.