You are driving on a rural highway behind a vehicle towing a heavy trailer as you begin descending a steep downhill grade. Which of the following best explains why you must increase your following distance beyond the standard three-second rule?
- The downhill slope increases gravity's pull on your vehicle, extending stopping distance, while the trailer ahead may sway or brake unexpectedly.Answer
- BThe standard three-second rule is only enforced in urban school zones, so a fixed five-second rule applies continuously on rural highways.
- CTowed trailers allow the lead vehicle to stop much faster on downhill slopes than solo passenger cars, reducing your reaction window.
- DThe posted speed limit automatically decreases by half on any downhill slope, requiring an increased time gap to stay above the minimum speed limit.
Answer
Increasing following distance to at least 4 to 5 seconds is necessary because gravity increases stopping distance on downhill grades and towed trailers introduce vehicle instability risks.
When descending a steep hill, gravity increases vehicle momentum and lengthens braking distance. Furthermore, vehicles towing heavy trailers are prone to trailer sway and may brake unexpectedly or slowly. Increasing the following distance to 4 to 5 seconds ensures sufficient time and distance to react safely.
Step-by-Step Solution
Key Concept
Speed control and following distance adjustments on steep downgrades and when trailing special vehicles
Estimated Time:1m 30s