When are paved roads most likely to be slickest?

Paved roads are most likely to be slickest minutes after the rain begins due to the combination of rain mixing with oils and debris that have accumulated on the surface. Initially, when it starts to rain, the moisture lifts these oils and contaminants, creating a slippery layer on the road. This condition tends to be particularly hazardous because drivers may not anticipate the sudden change in traction, increasing the risk of skidding or losing control of the vehicle.

As the rain continues and washes away some of these oils, road traction typically improves over time. Therefore, while heavy rainstorms and prolonged rain might cause slippery conditions, it’s right at the onset of rain that the roads tend to be the slickest due to the mingling of water with those previously mentioned substances.