The all cause rate is somewhere between once per 10.5 years according to Allstate [1], which at an average of 15,000 miles per year is ~157,000 miles, or once per 500,000 miles according to the Bureau of Transportation [2] numbers of police-reported accidents. The rate of injuries is 84 per 100 million miles (once per ~1.2 million miles or ~80 driver-years) and fatalities is 1.11 per 100 million miles (once per ~90 million miles or ~6,000 driver-years) by the same Bureau of Transportation statistics.

[1] https://www.allstate.com/resources/allstate/attachments/best... Page 4

[2] https://www.bts.gov/content/motor-vehicle-safety-data