I have 2 big long canal tunnels near where I live and I don't think they have ever had lights in them ( although I might be wrong ) if its just a bridge you have no need for lights in them so doubt that to.
Tow hitch, I believe that canal was a very secretive portable prototype, can be moved anywhere, if you rig a few shire horses up to it and give it a good pull and get back to us...