Travelling home from Norfolk. These road bridges remind me of a university group project where we had to build a bridge from balsa wood, glue and string. I remember coating the thing in PVA glue to make it as strong as possible. It had a triangular structure underneath and didn’t take the weight very well. It wasn’t the worst, but it wasn’t the best in class either. The tutor said it would have worked much better if we had built it upside down!!