Nearly half of all motorcycle crash fatalities are caused by: Do you currently have car insurance? Insurance is mandatory to drive in Ohio Yes I have insurance. But please show me your best quotes. No, please help me find the best insurance. Question Nearly half of all motorcycle crash fatalities are caused by: Answers Road conditions. The rider’s helmet. Alcohol impairment. Mechanical failure. Explanation Alcohol is a major contributor to motorcycle crashes, particularly fatal crashes. Studies show that 40 to 45 percent of all riders killed in motorcycle crashes had been drinking. This questions appears in the following tests: Pennsylvania Motorcycle Practice Test 5