With time running out, my Dad and I put in two long days of work on the train project to get it up and running. The bridge support ended up being the easiest part -- the 90 degree corners caused the most problems. One corner had to be taken down and re-tracked 3 times!
It's a relief to see my vision come to fruition. There were moments during testing that I thought it wasn't going to work. Thanks to everyone who believed in me and thanks to everyone who helped me. Trent, thanks for the idea for the bridge and the connectors. Dad, thanks for driving 800 miles just to end up working dusk-till-dawn on the train.