Hydroplaning — Hawaii Permit Test

Hydroplaning is when water on the road cannot be cleared fast enough and the tires ride up on the layer of water like a surfboard.

Tires floating on water have nothing to grip, so the car keeps going where it was headed whatever you do.

As speed increases, the water cannot be removed fast enough and the tires start to ride up on the layer of water like a surfboard.

Partial hydroplaning may start at 35 mph, and it gets worse with more speed and more water on the road.

A driver who thinks hydroplaning is only a freeway problem can lose grip on a wet town road.

Partial hydroplaning may start at 35 miles per hour (56 km/h).

At 55 mph in heavy rain, the tires may lose all contact with the pavement.

At highway speed in a downpour the car can be riding entirely on water before the driver feels any warning.

At 55 miles per hour (89 km/h) in a heavy rain the tires may lose all contact with the pavement.

When the tires lose all contact with the pavement, you cannot brake, accelerate or turn: you have no control over the vehicle.

A driver who stamps on the brake or yanks the wheel while floating gets a sudden lurch when the tires grip again.

When this happens, you cannot brake, accelerate or turn; YOU HAVE NO CONTROL OVER YOUR VEHICLE.

To prevent hydroplaning, keep good tread depth on your tires: worn or bald tires hydroplane at lower speeds.

Bald tires cannot push water out from under them, so they start to float at speeds a good tire handles easily.

Worn or bald tires will hydroplane at lower speeds.

To prevent hydroplaning, keep your tires inflated to the proper pressure and reduce your speed, since hydroplaning happens most at higher speeds.

A soft tire flattens out and floats on standing water sooner than one at the right pressure.

Insure that the tires on the vehicle are inflated to the proper pressure.

What is hydroplaning?

Tires riding up on a layer of water. Tires floating on water have nothing to grip, so the car keeps going where it was headed whatever you do. State of Hawaii Driver’s Manual, p.75: “As speed increases, the water cannot be removed fast enough and the tires start to ride up on the layer of water like a surfboard.”