Another general thunderstorm hazard is driving. The storm does not have to be severe to cause significant driving problems. One problem with driving in the rain is visibility (VIS). Even with good windshield wipers it can be frustrating to keep constant visibility through the changes in intensity of rain. Splashing and spraying from nearby vehicles can also reduce visibility. It is important to drive slower and more cautiously when it is raining. Since the visibility is reduced, it is important to turn on headlights during these rainy and wet conditions so that other drivers can see you better. Fogging up inside the car can be a problem during rain. This is because the humidity is high and it is easy to condense moisture on glass. Be familiar with the proper and best techniques to unfog the windows in your particular car in order to prepare for this potential problem.

An additional problem when it rains is that the roads become slicker. Water reduces friction between the tires and the road. The condition of the tire will play a role in how significant the problem with wet roads become. It should be assumed the cars around you and your car will have less friction with the road. This results in longer stopping distances when putting on the brakes. It also means it can be easier to lose control of the vehicle. The problem with less road friction is another reason to drive slower and with more caution during rain.