Is the road surface slippery when it just starts raining or after it has rained?

[DiMatteo]

The road surface is more slippery when it just starts raining than after it has rained. Reasons why the road surface is more slippery when it just starts raining: Before it rains, the road surface accumulates many substances that can cause the wheels to skid, such as dirt, oil leaks from passing vehicles, and rubber residue left on the road surface due to friction between the tires and the ground. When rainwater moistens these substances, it acts like a thin layer of lubricant. Precautions for driving in the rain: Maintain good visibility. Turn on the windshield wipers promptly, and when the weather is dim, also turn on the low beams and fog lights. If there is frost on the front windshield, turn on the air conditioning and direct the cold air toward the front windshield. If there is frost on the rear windshield, turn on the rear windshield heater to quickly eliminate the frost and avoid obstructing the view of vehicles behind.