Commercial Driver License (CDL) Class B Practice Test

What factors should be considered for selecting a safe speed down a downgrade?

1. Engine temperature and tire pressure

2. Total weight, length and steepness of grade, and weather

3. Vehicle model and driver experience

4. The presence of other vehicles on the road

The correct answer is: Total weight, length and steepness of grade, and weather

Selecting a safe speed down a downgrade is crucial for maintaining control of the vehicle and ensuring safety on the road. The correct factors to consider include total weight, length and steepness of the grade, and weather. Total weight is important because a heavier load can significantly impact the vehicle's braking ability and increase the risk of losing control. The length and steepness of the downgrade directly affect how quickly a vehicle will accelerate or lose control. A long or steep downgrade requires a slower, more controlled descent to prevent brake overheating and loss of stopping power. Weather conditions, such as rain, snow, or ice, can also dramatically alter road conditions, making it essential to adjust speed accordingly to maintain traction and control. Together, these factors provide a comprehensive understanding of how to safely navigate downgrades, ensuring that drivers are prepared for the specific challenges presented by the terrain and environmental conditions.