General Knowledge · Winter Driving
Which of the following is a clue that a road surface may be icy even though it does not look wet or icy?
Explanation
A driver can tell a road surface may be icy, even when it does not visibly look wet or icy, by watching for a lack of spray or splash coming up from the tires of vehicles traveling ahead, since water splashes when a road is merely wet but ice underneath tends to suppress that spray. This clue is especially useful on bridges and overpasses, which lose heat from both above and below and so tend to freeze before the rest of the road surface does. The other options fail for a shared reason: each invents a signal, CB radio reception, fuel economy, or engine temperature, that has no real connection to road surface traction and would not actually tell a driver anything about ice.
Source: 49 CFR 383.111(a)(12)(i)
Related Winter Driving questions
- Under 49 CFR 393.75, what is the minimum tread depth required in a major tread groove of a commercial motor vehicle's front (steering) tires, and how does that compare to its other tires?
- Under 49 CFR 383.111(a)(12)(i), which weather conditions does federal regulation specifically name as examples of the "bad weather" a CDL knowledge test must cover?
- Why does guidance for driving on icy or snow-covered roads advise against using the engine brake or speed retarder?
- After driving a commercial motor vehicle through a deep puddle or standing water, why does guidance recommend applying light, steady pressure to the brakes for a short distance afterward?