If you have (I hope) made bug-out plans, you looked at all the bridges on all your possible routes...
This resource makes this much easier and gives you pictures too.
https://bridgehunter.com/Drill down to your state and county for the list and link to data about each bridge.
I noted several "abandoned" railroad bridges which might be of immense help if the main road bridges are inaccessible, for any of an number of reasons..