As you guide your car around a bend contaminated with a sudden diesel spillage, the front wheels lose adhesion, causing understeer where the vehicle continues pushing straight ahead despite your steering input. In what sequence should you carry out the following corrective actions to restore steering control?
- 1Smoothly ease off the accelerator and refrain from applying harsh footbrake pressure to remove excessive longitudinal load.
- 2Briefly reduce the steering lock by easing the steering wheel back towards the straight-ahead position.
- 3Allow the front tyres to re-establish physical traction and steering response with the road surface.
- 4Gently and progressively steer back along the intended curvature of the road.
Answer
The correct sequence begins with smoothly easing off the accelerator without harsh braking, followed by reducing excessive steering lock towards straight-ahead, waiting for the front tyres to regain grip, and finally re-applying smooth steering towards the intended line of travel.
When front-wheel skid (understeer) happens, the front tyres have lost grip due to excessive speed, reduced surface friction, or excessive steering angle. Easing off the throttle reduces tyre load, while unwinding the steering wheel decreases the slip angle to allow the rolling tyres to regain grip. Only after traction is re-established should the driver smoothly steer back onto the intended path.
Step-by-Step Solution
Key Concept
Understeer occurs when front tyres exceed their limit of adhesion; correcting it requires removing drive/braking forces and reducing the steering angle to allow tyre tread to re-grip before steering into the bend.
Estimated Time:1m 30s