Ice bridges on Winnebago

Car Bridge Question.  For those of you setting up bridges.  What is the minimum and maximum distance between rails.  I have on a number of trips had to cross these bridges on my atv.  This requires riding on top of the rails. It has been hairy on a few occasions.  Do you have a set distance that you try and follow?  Has anyone thought of placing them a little closer together to allow for easier atv access.  It always seems as if there is plenty of room to accommodate my  fullsize truck.

Hey Fish Hound.  I get that there are atv bridges out there.  Problem is I am not always wanting to run miles to use one and to be honest,  I ripped holes in my flip shanty bottom twice as have my friends using them.  The one in Oshkosh has a sharp chunk of metal that is a hazard.  I have plastic welded a half dozen plastic tubs that were gashed.  That is why we started using the car bridges.  I asked about the width for a specific reason though.  I did not do it to bash the hard work done by the fish clubs. I love those guys.  I wanted to know if there was a specific width because I was considering putting on 2" wheel spacers.  That would increase my width 4" and possibly allow me to travel on the actual bridge.

Many shanties have a wheel base wider than that of a truck too so I'm sure they try and split the distance.

There are some clubs that place ATV bridges as well. SUNK does a great job of tracking and posting plowed roads and bridge locations.