Well, the average human reaction time is 215ms, which would be considered unacceptable in online-gaming, where 50ms would already be on the high side of things, I normally see 30ms or so.

Let's assume 50ms or 20 updates per second, and a car driving at 40m/s or about 145kmh / 90mph, the reaction time of the of the computer is after the car moved 2 meters (about 6.5 feet). A human would only react after about 8.5 meters (about 28 feet) - quite the difference.