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Question

Difficulty: MediumSpeed and Road Conditions

While operating a commercial vehicle across an elevated highway bridge during freezing temperatures, the driver notices ice forming on the mirror brackets and feels the steering wheel become unusually light. What is the safest immediate action the driver should take?

  1. A
    Engage the engine retarder at its highest setting to slow the vehicle down steadily without using the service foot brake.
  2. Ease off the accelerator gradually to slow the vehicle to a crawl without applying the brakes or engaging the engine retarder.Answer
  3. C
    Maintain cruising speed across the bridge deck and apply firm service braking once entering the upcoming curve.
  4. D
    Apply intermittent service braking while maintaining highway speed, assuming total stopping distance remains unchanged as long as perception time is fast.

Answer

Ease off the accelerator gradually to slow the vehicle to a crawl without applying the brakes or engaging the engine retarder.
When ice begins forming on vehicle mirrors and the steering wheel feels light, the vehicle is encountering black ice—an extremely hazardous condition often found first on bridges and overpasses. Commercial driving standards dictate that on icy road surfaces, drivers must adjust their speed down to a crawl. Deceleration should be achieved smoothly by easing off the throttle rather than applying the service brakes or activating engine retarders, both of which can break remaining wheel adhesion and trigger a jackknife.

Step-by-Step Solution

1
Identify the environmental and tactile indicators of extreme traction loss.
Recognize that ice on the mirrors, cold ambient conditions on an overpass, and a 'light' steering feel confirm the presence of black ice.
Elevated structures freeze before other roadway segments, and loss of steering feedback signals that the front tires are losing grip on ice.
2
Determine the required speed adjustment and operational safeguards for icy pavement according to CDL safety standards.
Decide to decelerate to a crawl by gently easing off the throttle while ensuring the engine retarder is completely disabled and hard braking is avoided.
Official CDL standards require reducing speed to a crawl on ice; any abrupt deceleration, brake application, or retarder drag will lock the drive wheels and provoke a loss of control.

Key Concept

Recognizing slippery road indicators (black ice) and executing proper speed reduction to a crawl without retarder or harsh brake engagement.
Estimated Time:1m 0s
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Topics

Speed and Road Conditions

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