The question isn't how often it happens. The question is whether it's reasonable that Arbrey would have thought that the people behind any door he knocked on would be likely to let him in to their house and bar the door to the people chasing him with guns.
This doesn't even have to be a conscious thought, just even a vague "I'll find no help here" which means that it wouldn't even occur to him to try.
And that will be dependent on what he believed the make-up of that neighbourhood to be, him impression of those demographics, and his past experiences with them.
I think the other issue is whether Americans are allowed to kill people knocking at their door? Just going up to knock on a door puts you at risk of being shot dead. Why multiply your risk?
https://www.bbc.co.uk/news/world-us-canada-50063364