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Difficulty: MediumSpeed and Road Conditions

If a commercial motor vehicle begins to hydroplane on a water-covered road surface, the driver should immediately apply the service brakes firmly to restore tire contact with the pavement.

Answer: Answer

Answer

False
Applying the brakes during hydroplaning is dangerous because the tires lack traction; braking locks the wheels and causes loss of directional steering control. Commercial drivers should release the throttle and push in the clutch instead.

Step-by-Step Solution

1
Analyze vehicle dynamics during hydroplaning.
During hydroplaning, tire treads cannot channel away standing water quickly enough, causing the tires to lose contact with the road and ride on a thin layer of water.
Understanding the loss of surface friction is essential for selecting appropriate driver actions.
2
Evaluate the physical effect of braking on water-cushioned wheels.
Applying brakes to wheels that have zero surface traction locks them immediately, eliminating steering control and greatly increasing the risk of skidding or jackknifing.
Braking inputs during hydroplaning aggravate vehicle instability rather than restoring traction.
3
Determine the standard CDL recovery procedure.
The driver must release the accelerator and push in the clutch, allowing the vehicle to decelerate smoothly until the tire treads re-establish direct contact with the pavement.
Gradual deceleration without wheel lockup maintains directional stability.

Key Concept

Hydroplaning Dynamics and Driver Response
Estimated Time:1m 0s
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Topics

Speed and Road Conditions

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