The [RF] Basic Bridges Mod allows you to build bridges. Technically, you can also create piers or even a boardwalk, it’s really up to you. No special research is required. All you need is wood, stone or metal. And a bit of steel for reinforcement if you’re building over deep water.
All bridges support light construction, so you can, for example, use a bridge to run a power conduit across a river. Additionally, heavy bridges (those built from stone or metal instead of from wood) will support heavy construction, so you can actually place walls on them.
The [RF] Basic Bridges Mod is available in English and Traditional Chinese (by Alane).