I think it just becomes ingrained in your subconscious to expect/anticipate the worst possible maneuver. In a previous life I was an over-the-road truck driver. After several years it just occurred to me one day that I must have some type of ESP--I knew what the car ahead of me was going to do before they did it. I could see a car at an intersection I was approaching and I just somehow knew they were going to pull out in front of me. I would start checking my mirrors and try to find an escape route and/or move my foot over the brake pedal.
It may be some type of learned behavior--maybe a behavior modification, Pavlov's dog kind of a thing.