Examkin

Soru

Zorluk: OrtaDriving in Fog

A commercial motor vehicle is traveling along an undivided highway when dense patch fog suddenly restricts forward sight distance to 150 feet. What operational adjustment must the driver make to maintain safety under these conditions?

  1. A
    Switch the auxiliary engine retarder to maximum power to assist in decelerating without locking the service brakes.
  2. Reduce travel speed so the total stopping distance—including perception, reaction, and braking distances—remains well within the visible distance ahead.Cevap
  3. C
    Close the following distance to the lead vehicle to maintain continuous visual contact with its rear marker lights.
  4. D
    Maintain normal cruising speed as long as the mechanical braking distance alone does not exceed the visible sight distance.

Cevap

Reduce travel speed so the total stopping distance—including perception, reaction, and braking distances—remains well within the visible distance ahead.
Under commercial driving safety standards, a driver must never overdrive their visibility. The vehicle's total stopping distance—which encompasses perception distance, reaction distance, and actual braking distance—must always be shorter than the distance the driver can clearly see ahead.

Adım Adım Çözüm

1
Evaluate the visibility constraints and road surface condition caused by fog.
Identify that reduced forward sight distance requires proportional deceleration and that atmospheric condensation can create slippery pavement.
Commercial vehicles require substantial distance to stop, which must never exceed the driver's forward sight limit.
2
Calculate stopping requirements incorporating all three components: perception distance, reaction distance, and vehicle braking distance.
Determine that total stopping distance must be less than the 150 feet of visibility.
Relying strictly on braking distance ignores critical lag time during perception and reaction, leading to collision hazards.
3
Select the correct speed and control management strategy according to official CDL guidelines.
Slow down appropriately, avoid retarder use on slick surfaces, and maintain generous space ahead.
These combined actions guarantee vehicle control and collision avoidance in adverse weather.

Anahtar Kavram

Sight Distance and Speed Management in Fog
Tahmini Süre:1m 0s
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Konular

Driving in Fog

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