Here is a little 50′x28′ bridge I designed for a accelerated bridge construction demonstration. Not a very exciting design but the bridge was built in five days. The sound is off because, a) its me and 2) I used two different programs to record the sound.
Updated: Some more things about this bridge. I won a small design award for it. The contractors had ten days for construction and were worried that they would not make it but they did and received a bonus. Typically the beams would not be the driving surface. You would usually place a overlay but this is on a gravel road, so no salt is applied to the road in winter. Its an experiment!