How long should drivers be vigilant when the pavement has just started to get wet?

When the pavement has just started to get wet, drivers should be especially vigilant during the first few minutes after the rain begins. This is because the initial period of rain can create a very slippery condition due to the combination of water and dirt or oil that hasn't yet washed away. During these first few minutes, the risk of hydroplaning and losing traction is significantly heightened as vehicles might not have optimal grip on the wet surface.

Being alert during this time helps drivers better react to any sudden changes in road conditions or behaviors of other vehicles. As the rain continues and more water is present on the pavement, conditions may stabilize, but it's crucial to maintain awareness throughout any wet driving conditions. Therefore, while the first half hour is also an important time to be cautious, the most critical period is actually those first few minutes when the rain begins to fall and the pavement is less predictable.