Update: MassDOT wants to open the new bridge by 2030, sooner than what they had been saying lately:
https://mass.streetsblog.org/2025/06/25/tonight-massdot-hosts-online-hearing-for-mystic-river-car-free-bridge-project
The approach roads are stacked, so it won't be possible to switch traffic to one side or the other while one level is being demolished and rebuilt. I'd say close the bridge for a couple of years and just build the new structure in the same place on the same footprint.
I think its more a matter of prioritizing what money we do have for infrastructure improvements. Should we spend money on reconfiguring the ramps on an interchange on Route 9. or spend it on this footbridge over the Mystic River? I would vote for the latter.
I need to agree with F-Line on this one. The tracks have been there for 178 years, and converting the LRV line into HRV would not significantly enlarge the footprint. Any increase in noise can be mitigated by noise barriers.
Is building a more direct pedestrian connection to the Assembly Square station from the proposed Footbridge an official part of the project? I hope so.