The construction effort on 520 is about to move to the West side, after a long, long slog of a project. The last pontoons will be on the lake by November (if the creek don’t rise) and the details of the Eastside project will get finalized. The communication below is from Julie Meredith, the Program Administrator for the entire project (and one of my favorite engineers.)
If you check out some of the links you’ll see that the part of the new bridge that connects to the existing 520 is mostly temporary. it’s a complicated dance to keep the project moving forward without totally disrupting