One of the most common reasons for serious rear-end accidents and collisions in the San Francisco Bay area and the surrounding areas during rain is failure to maintain safe distance with the car in front. It seems to be our nature to not fully appreciate the danger of following someone too closely on the road until we face a situation where we need to suddenly stop a car, and we realize how little control over our car we have when the road is wet or even mildly moist.
Just the other day, just a few minutes after it started raining I saw a car approach an intersection, just a few feet before the stop light the driver realized that he might run the read light and he abruptly but forcefully applied his breaks. Had it not been raining, he most likely would have stopped just slightly protruding into a crosswalk. However, because of the slippery conditions (and probably because his tires weren’t in the best condition), he car slid forward and swerved into the middle of the intersection. He was lucky that it was late at night, and there were no upcoming traffic from any direction. Had it happened during the busy hours of the day, he would likely have been “t-boned” and severely injured.
I really do believe that one of the great exercises that every driver can do to learn and appreciate how difficult it is to stop a car in rainy conditions and avoid a collision, is by getting in a car at night during rain, finding a very safe area for experimenting, go up to 20-30 miles an hour and try to stop abruptly right before the intersection or a crosswalk, to just see how much further your car will end when stopped than you would normally expect.