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Zorluk: ZorWinter Driving

A freight driver is traveling on an undivided rural highway during dense freezing fog with an ambient temperature of 28°F. The roadway appears glossy, but road spray from the tires of a preceding vehicle suddenly vanishes, indicating the formation of black ice. What immediate action should the driver take to maintain vehicle stability and prevent a catastrophic drive-wheel skid?

  1. A
    Activate the secondary engine retarder to slow the drive wheels without touching the service brake treadle.
  2. B
    Decrease following distance to remain within the visual tire tracks of the preceding vehicle and prevent ice buildup under the tires.
  3. Disengage the engine retarder, refrain from sharp steering or harsh braking, and allow the vehicle to ease off speed naturally.Cevap
  4. D
    Apply hard foundation brakes while steering aggressively toward the road shoulder to find gravel traction.

Cevap

Disengage the engine retarder, refrain from sharp steering or harsh braking, and allow the vehicle to ease off speed naturally.
When black ice forms, tire traction is drastically diminished. Engine retarders supply braking force solely to the drive wheels; on slippery surfaces, this auxiliary retarding force can instantly break drive-wheel traction and cause an unrecoverable jackknife. CDL safety standards require drivers to turn off engine retarders on wet, icy, or snow-covered surfaces and avoid any sudden steering, acceleration, or braking inputs while gradually decelerating.

Adım Adım Çözüm

1
Identify the critical environmental cue and surface condition.
Recognize that the sudden disappearance of tire spray from preceding traffic at below-freezing temperatures indicates the road surface has transitioned to black ice.
Detecting black ice early allows the driver to adjust controls before tire slip occurs.
2
Deactivate auxiliary retarding devices immediately.
Turn off the engine brake or retarder system.
Retarders deliver braking drag directly to drive axles, which readily induces drive-wheel spin loss and jackknifing on ultra-low-friction surfaces.
3
Modulate vehicle speed through gentle, gradual deceleration without abrupt inputs.
Maintain smooth steering alignment and ease off the accelerator without abrupt brake applications.
Sudden mechanical inputs exceed the minimal friction threshold available on ice, leading to skidding.

Anahtar Kavram

Black Ice Hazard Recognition and Retarder Management
Tahmini Süre:2m 0s
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Konular

Winter Driving

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