Driving on Wet Roads

Do not accelerate and do not brake suddenly. Keep your foot lightly on the gas, hold the steering steady, and guide the car forward until the tires regain contact with the road. Sudden inputs while the tires are riding on a film of water are what turn a brief hydroplane into a full loss of control.

Because they present the same core dangers as winter roads: less available grip and longer stopping distances. Snow and ice trigger caution automatically in most drivers. Rain does not, so drivers maintain dry-weather speeds and following distances on a surface that no longer supports them.

Tread depth and groove design that evacuate water from the contact patch, plus a compound formulated to grip a wet surface. As tread wears down, water evacuation capacity drops and hydroplaning risk rises. This is why replacing tires at 4/32 of an inch rather than waiting for 2/32 is worth considering if you drive in rain frequently.

In the first several minutes of rainfall after a dry spell, when water lifts accumulated oil and rubber residue off the surface before washing it away. That mixture is more slippery than either surface alone. Standing water in ruts and at lane edges is the other high-risk situation, because it causes hydroplaning at lower speeds.

Meaningfully more than in dry conditions, and more again if the rain is heavy or there is standing water. The principle is that you need enough space to stop completely if the vehicle in front stops suddenly. If traffic does not allow that gap, reduce speed until it does rather than closing up.