Roadways are the most slippery:

1. During a heavy downpour.
2. After it has been raining for awhile.
3. During the first rain after a dry spell. ✓

Answer: C. During the first rain after a dry spell.

Roadways are most slippery during the first rain after a dry spell, when oil and dust have not been washed away.

Why this is the answer

The handbook says pavement can be very slippery when it starts to rain. It points out that this is especially true after a dry, hot stretch, because oil and dust on the road surface have not been washed away. That matches the first rain after a dry spell. The handbook's advice is to slow down at the first sign of rain, drizzle, or snow, so the start of rain is the condition to watch.

Why the other answers are wrong

• A. During a heavy downpour. — A heavy downpour is not the condition the handbook singles out; it warns about the start of rain, when oil and dust are still on the pavement.
• B. After it has been raining for awhile. — The handbook does not point to a long rain as the most slippery time; it emphasizes the beginning of rain after dry weather.

Remember it

Watch the first rain, not the worst rain.