Does that lake/bridge road have any sort of pedestrian sidewalk? Some of the bridges here in Portland are pretty icky to ride over (steel grates! ) and so a lot of cyclists use the sidewalk in that case.

Also, you'd be surprised how effective a phone call to the department of transportation or city sanitation can be if you let them know there is a ton of debris on a specific road shoulder. It's worth a try, chances are they'll come out and sweep it.