Car Accident and Injury Factors The majority of automobile accidents are caused by driver error. A tendency to speed and drive aggressively leads to more accidents, and more car accidents in Arizona are caused by drivers not driving appropriately for the road or weather conditions than any other violation. Accidents are a result of drivers driving too fast for the road condition than any other driving violation. There are additional contributory factors to motor vehicle accidents unrelated to the driver, such as road design flaws. A common non-driver cause of motor vehicle accidents is a stuck gas accelerator. A car with a tendency to roll when driving can also lead to a crash, even if the driver is driving at the appropriate speed.