Re: Cruise Control and Hydroplaning
From: Jeff S.

I think the explanation needs to be clearer. Using cruise control in the rain is only hazardous because the car doesn't automatically slow down for slippery conditions. It also will try to continue at the preset speed until you disengage it (hit the brakes) even if you lose control. The original rumor makes a big deal about the car speeding up dramatically, which is absolutely impossible if you have lost traction with the road. You may lose control, you probably wouldn't slow down much, but the car is certainly not going to accelerate and take off like an airplane.

The trooper's comment is almost as bad, when he says cruise control "won't allow you to slow down." Excuse me, but just touching the brakes cancels the cruise control, and isn't hitting the brakes how you would try to slow down? True, a person could panic and do nothing, which would be the same as holding his foot on the gas, which obviously would be bad.

So, while it makes sense not to use cruise control when road conditions are bad to prevent you from going too fast for the road conditions, there's nothing magical about it that would cause your car to accelerate drastically. If you don't think that would be magic talk to a physics professor — it takes force to make an object accelerate, and you can't exert force through hydroplaning tires when there's no traction.