Editing Roman bridge (section)

=== Pontoon bridges ===

[[Pontoon bridge]]s were built by laying boats from side to side across a river.<ref name="mcgeough" /><ref name="bunson" /> During [[Julius Caesar]]'s [[Gallic Wars|campaign]] in [[Germania|Germany]], he built [[Caesar's Rhine bridges|bridges]] by driving wooden piles into the [[stream bed]] from floating platforms and fixing beams at [[right angle]]s across them to create trestles. [[Trajan]] built another bridge supported by stone during the [[Trajan's Dacian Wars|Dacian Wars]].<ref name="corbishley" /> Roman engineers gradually developed new techniques to build bridges, such as oval-shaped bases and pierced bases to facilitate the movement of water. Many bridges would have [[marble]] [[relief]]s or [[carving]]s, but these bridges were likely used exclusively by [[Roman Constitution|government officials]] because of the difficulty and expense of carving marble artwork.