CDL Air Brakes TestUsing Air BrakesHard
A driver is operating a commercial vehicle with air brakes on a slippery road. To prevent skidding and maintain control during a moderate stop, which braking technique should be used, assuming the vehicle does NOT have ABS?
- AStab braking.
- BControlled braking.
- CEngaging the parking brake briefly while applying service brakes.
- DAggressive, full-pressure braking.
Show answer & explanationAnswer & explanation
Correct answer: B. Controlled braking.
For a moderate stop on a slippery road with an air-braked vehicle without ABS, 'controlled braking' is the most appropriate technique. This involves applying the brakes as hard as possible without locking the wheels, constantly monitoring the vehicle's behavior, and easing off if a skid begins.
Why the other options are wrong
- A. Stab braking is for emergency stops where maximum stopping power is needed; for a moderate stop on a slippery road, it might be too aggressive and induce a skid.
- C. The parking brake should never be used to slow a moving vehicle, especially on slippery roads, as it can cause an uncontrollable skid.
- D. Aggressive, full-pressure braking on a slippery road without ABS will almost certainly lead to immediate wheel lock-up and a loss of control.
Controlled Braking (Slippery Roads)
A technique for braking on slippery surfaces with air-braked vehicles without ABS, involving applying firm, consistent pressure just short of wheel lock-up to maintain steering control.
- For vehicles without ABS.
- Apply brakes as hard as possible without skidding.
- Maintain steering control.
- Ease off if wheels begin to lock.
Memory trick: Slippery roads? Control your stop, don't let it pop!