Roads are the most slippery right after it begins to rain because: Question Roads are the most slippery right after it begins to rain because: Answers The water mixes with the oil and grease on the road that have not yet washed away. Roads are naturally slippery. The gravel gets washed into the middle of the lane. Explanation 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. This questions appears in the following tests: Alaska Class B Knowledge Test Connecticut Passenger Iowa Class A Knowledge Test Iowa Passenger