CDL Air Brakes TestUsing Air BrakesHard
A commercial driver is operating a vehicle equipped with air brakes. They need to brake suddenly to avoid an obstacle but want to maintain steering control. If the vehicle is NOT equipped with ABS, which braking technique is most appropriate?
- AEmergency Braking (full pedal).
- BControlled Braking.
- CLight, continuous braking.
- DStab Braking.
Show answer & explanationAnswer & explanation
Correct answer: D. Stab Braking.
When an air-braked vehicle without ABS needs to stop quickly while maintaining steering control, 'stab braking' is the appropriate technique. This involves applying the brakes fully until the wheels almost lock, then releasing them to regain steering, and reapplying them forcefully.
Why the other options are wrong
- A. Emergency braking (full pedal) without ABS would likely cause wheel lock-up, leading to loss of steering control and potentially a jackknife or skid.
- B. Controlled braking is a less aggressive technique used for normal stops or slowing, not typically for sudden emergency stops where maximum braking is needed intermittently.
- C. Light, continuous braking is insufficient for an emergency stop and would result in a longer stopping distance.
Stab Braking
An emergency braking technique used in air-braked vehicles WITHOUT ABS, involving full brake application followed by a brief release to prevent wheel lock-up and maintain steering, then reapplying.
- For vehicles without ABS.
- Apply brakes fully, then release.
- Prevents wheel lock-up.
- Maintains steering control.
Memory trick: No ABS? Stab and steer, clear your fear!