If you notice a crack in your windshield, get it fixed as soon as possible. Unlike a door ding or a bit of rust, it can cause serious safety problems. Even a small crack is significant because temperature changes can increase its size and its impact on your safety. Here are four hazards of a cracked windshield: It No Longer Serves as A “Shield” A windshield does more than protect you from the airstream moving past your car. It prevents small rocks and similar sized road debris from striking you.