It’s not even close to 500 miles unless you were on the interstate for 500 miles driving strait and even then it’s doubtful.In general (No route limitations):
If you define accident as hitting another car or pedestrian,
If I didn’t intervene at all, most of my risk would be from pissed off people behind me. Or someone rear ending me.
Considering all of this, probably around 500 miles
If I could choose a 5 mile route, probably 10k miles or more
I feel like it is 10-15 miles on well marked roads with stoplights and 0-5 miles on other roads.