Commercial Driver License (CDL) Class B Practice Test

If stopped on a hill, how can you start moving without rolling back?

1. Switch off the ignition

2. Partly engage the clutch before releasing the brake

3. Accelerate quickly

4. Use the handbrake only

The correct answer is: Partly engage the clutch before releasing the brake

Starting on a hill without rolling back requires a careful technique in managing both the clutch and the brake. By partly engaging the clutch before releasing the brake, you create a balance that allows for a smoother transition from a stationary position to moving forward. This technique utilizes the engine's power and allows the driver to engage the forward motion of the vehicle while maintaining control, minimizing the risk of rollback. The method of partly engaging the clutch effectively raises the engine's RPMs slightly while the brakes are still applied, which helps hold the vehicle in place. As you gradually release the brake and fully engage the clutch, the vehicle moves forward without slipping back down the hill. It is essential in this scenario to ensure that the vehicle’s power is directed to the wheels without losing momentum. In contrast, switching off the ignition would prevent the car from moving altogether, and accelerating quickly without proper clutch control could lead to loss of traction or a sudden lurch, potentially causing dangerous situations. Relying only on the handbrake could also be insufficient because, while it can prevent rollback, it does not assist in the smooth transition necessary for a safe start on an incline. This controlled technique is vital for ensuring a safe and effective start on a hill.