Roads are the most slippery right after it begins to rain because:

Question

Roads are particularly slippery when it first begins to rain. The water mixes with oil drippings on the road that have not yet washed away, creating a slippery and dangerous mixture.

Accepted Answer

The water mixes with the oil and grease on the road that have not yet washed away.

Answer

Roads are naturally slippery.

Answer

The gravel gets washed into the middle of the lane.