During a rain shower at what time is the road surface likely to be most slippery?

The road surface is most likely to be slippery during the initial moments of a rain shower, typically within the first 10 to 15 minutes. This is because rainwater mixes with oil and debris that have accumulated on the road, creating a slick layer. As the rain continues, the water helps to wash away these substances, gradually improving traction. However, caution is still advised throughout the rain, as conditions can change rapidly.