Much of Summer St has a new, curb-barrier-separated, asphalt bike way that needs to be mapped. (The satellite images are also out of date.)

Both of the D branch bridges (this one outbound, the other one nearby inbound) seem to be named "Red Bridge" or "Red Bridge Viaduct". But I'm not sure if that name also applies to more (like the part carrying the E branch as well).

This is not a 2-way cycleway, it's a painted 1-way bike lane, next to a narrow sidewalk. It is a well-known danger.