I was never able to fully develop and use this bridge. I got this idea from talking with a Science Olympiad coach in Ohio. Now I wish I had gone ahead and put more work into this. The next year, the bridge rules changed so that I could not use this concept.
The trick was to get the arches to the perfect length, so that they barely fit into the loading device. I had made these arches a bit too long. When I tested the bridge, the arches were already bent out-of-shape, so it did not hold enough weight. I fully believe that this bridge concept can go very far.
As you can see, this bridge had a roadbed, which was supposed to allow a hotwheels or matchbox car to roll freely across. BAD DRIVER!