CN Julien Dubuque Drive Bridge
Photo taken by John Marvig in April 2018
BH Photo #426574
I believe they’re “French” drains, likely installed because the road surface under the bridge is at a low point. A French drain is just a grate with gravel or other soil underneath that water can pass through to the ground water table. This drain type doesn’t require any plumbing to carry water away.
Yeah I believe they are. The Mississippi River is rather close to this location, and I assume a lot of runoff water makes it’s way to the bridge. It might be possible this was originally built to cross a creek, but a road was built underneath?
Are those drains along the sides of the roadway?