Skid Recovery and Emergency Maneuvers
Skid Recovery and Emergency Maneuvers
This domain tests what to do when traction is lost or a system fails. The exam focuses on brake skids, drive-wheel skids, trailer skids, brake failure, tire blowouts, and off-road recovery.
Core rules
- A skid happens when tires lose traction because of overbraking, too much acceleration, or too much steering input.
- If wheels lock, release the brakes to get them rolling again, then steer and reapply pressure gently.
- If the drive wheels spin or the trailer begins to swing, ease off the accelerator and avoid abrupt steering. Overcorrecting can cause a second skid.
- In a brake failure, downshift, use engine braking, and apply the parking brake gradually if it will help. Do not instantly lock the spring brakes at highway speed.
- After a blowout, hold the steering wheel firmly, keep the vehicle straight, ease off the accelerator, and slow gradually before pulling off the road.
Worked example
A tractor-trailer is braking on a wet road when the trailer brakes lock and the trailer begins to swing. The driver releases the brake pedal, lets the wheels roll, steers to keep the tractor aligned with the trailer, and then reapplies the brakes lightly. Holding the brake pedal down would keep the trailer wheels locked and worsen the swing.
Traps that cost marks
Slamming on the brakes, jerking the wheel, accelerating out of a skid, and waiting too long to release a locked brake are common errors. Do not make a hard turn while braking in a curve.
Key points
- Release locked brakes to restore rolling traction.
- Ease off the accelerator during a drive-wheel or trailer skid.
- Avoid abrupt steering and overcorrection.
- For brake failure, downshift and use engine braking.
- After a blowout, hold steady and slow gradually.