CDL Combination Vehicles TestDriving Combination Vehicles SafelyEasy
A commercial driver is operating a combination vehicle and encounters dense fog, significantly reducing visibility to less than 100 feet. What is the safest and most appropriate action the driver should take?
- AMaintain current speed and use hazard lights to make the vehicle more visible.
- BSlow down significantly, turn on low beam headlights and fog lights, and increase following distance.
- CTurn on high beam headlights and follow the tail lights of the vehicle ahead closely.
- DPull over immediately to the nearest shoulder, regardless of where it is, and turn off all lights.
Show answer & explanationAnswer & explanation
Correct answer: B. Slow down significantly, turn on low beam headlights and fog lights, and increase following distance.
In dense fog, low beam headlights and fog lights provide better visibility without reflecting glare back into your eyes. Reducing speed and increasing following distance are crucial for safety due to reduced reaction time.
Why the other options are wrong
- A. Maintaining speed in dense fog is extremely dangerous. Hazard lights are for disabled vehicles, not for driving in fog.
- C. High beams reflect off fog, worsening visibility. Following too closely is always dangerous, especially in low visibility.
- D. Pulling over to the shoulder can be dangerous if other drivers cannot see you. Only do this if it's impossible to proceed safely AND you can get completely off the road and use warning devices.
Driving in Fog
When driving in fog, reduce speed, use low beam headlights and fog lights, and increase your following distance to ensure safety and visibility.
- Low beams/fog lights only.
- Reduce speed.
- Increase following distance.
Memory trick: Slow, Low, and Far to Go.