You can calculate the probability on pretty much everything. However lots of factors come into play in a situation like this and the variables typically mediate each other. You would have to have lots and lots of random data about rates, for areas, days, times, ..., etc.

You may be able to look at accident rates for areas, the population numbers, etc., but then there are many other factors such as do the rates take into account people wiith multiple accidents, etc. You could figure it out, but it would end-up being a dissertation. You can probably just go with, the probability is very very low, but exists.