- When you drive on a wet road, the grooves channel water away from the tire. Having adequate tire tread depth helps your tire stay in contact with the road. If your tires are “bald,” the grooves between the tread won’t be deep enough to channel water away. As a result, a wedge of water will build up in front of the tire and your car could hydroplane. The deeper the tread, the better the degree of traction that your tires will provide on wet pavement.