Videos on bridge building can be found on a number of websites. Ron Hazelton Home Improvement Online (RonHazenton.com) has a video on how to build a wooden foot bridge. The website lays out detailed instructions in several steps, each accompanied by a separate video. The resulting laminated bridge spans 12 feet, rests on heavy block piers and has side rails and decking.
ScienceKids.co.nz has a video that explains the differences between three kinds of bridges. The video discusses the various circumstances that call for the construction of a cable-stayed, suspension or arch bridge. It explains how engineers take into account the location of the bridge and its intended purpose when deciding on the use of a particular building style.
MotherEarthNews.com has a tutorial on how to build a log bridge. The instructions are accompanied by a slide show featuring simple illustrations of each step.
Crayola.com offers instructions on how to build a model suspension bridge. Using several basic supplies that can mostly be found around the house, the model bridge is simple enough for kids to make.
PBS.com shares an informational video on why it takes modern bridges in the United States much longer to build than it did in the 1970s.