Copied from an American site, apologies to those who are already aware. Driving with Cruise Control On Wet Pavement In our October newsletter, the Helpful Hints section suggested turning off cruise control to avoid hydroplaning and a possible accident when driving on wet pavement. Additional information: Wet-road driving is full of dangers that are not always apparent. Roads constantly accumulate oily substances and this residue settles deep into the pavement. Rain brings the residue back to the surface, making roads especially slippery during that first hour of downpour or even misting. Under these wet conditions drivers are likely to experience reduced control, and are cautioned to be extra careful for the first half-hour after it begins to rain. Just a thin layer of water lying on pavement can send an unsuspecting car hydroplaning into another lane or even off the roadway. What is hydroplaning? In rain, a layer of water builds up beneath your tires. As you drive at higher speeds, the car begins sliding on this layer and can cause you to loose all physical contact with the ground. The car's wheels skim along the water's surface instead of making contact with the road. This is called hydroplaning, and greatly reduces control, allowing even slight gusts of wind to cause your car to skid. Thus it is highly advisable to avoid high speeds during rains. The only way to stop this wheel-spin and maintain control is to immediately reduce power. However, an activated cruise control system will continue to apply power, keeping the wheels spinning. By the time you disengage the cruise control, you may have lost control.