Left hand, meet right hand: MBTA warns commuter rail could quickly collapse if MassDOT demolishes Charles River bridge for its Allston turnpike project

was staring us in the face this whole time.

MBTA service would cease within weeks, due to an inability to conduct required maintenance.

Let's take a trip all the way back to 2012. At that time, the Grand Junction bridge was closed with very little notice because of deterioration and trains were forced to make the 108 mile loop out to Ayer, down to Worcester, and back into Boston. This went on for two months of temporary repairs, then it was closed down again in the spring for three more months. So while there are definitely operational complexities, Commuter Rail service would not cease to exist; the T would have to spend additional money and time moving the trains around. (There was another several-week closure in 2018 for construction on the Talbot Street outfall in Cambridge under the Grand Junction.)

Additionally, the trip via Ayer and Worcester has gotten faster since CSX has bought out Pan Am and made upgrades to the Worcester Secondary the trains run along. This has increased the track speed for the 25-mile trip from 10 mph to 25 mph (theoretically passenger equipment could go faster, but likely would not) cutting down the trip time from about three hours to closer to one. On the other hand, there is increased freight service on the line, but Amtrak and MBTA equipment moves could be scheduled to take advantage of slots in front of or behind through freight trains. Given that, equipment moves would take about 4 hours to go "around the horn": an hour out to Worcester, and hour up to Ayer and an hour into Boston, plus additional time spent switching and waiting for track clearance. The marginal additional time is about 3 hours, since the trip across Cambridge isn't exactly fast (10 mph, plus a full stop at each grade crossing, plus switching).

So, no, rail service would not cease, but the T would have to spend more time and money moving trains around than it does over the Grand Junction. I'd estimate that between CSX trackage fees and crew time it would be somewhere on the order of $5 million per year. The question then becomes, how much would closing the Grand Junction for some period save from the overall cost of the Allston project? There might be a lot of things which become easier if you don't have to worry about threading through and around an active (if infrequently-used) rail line. If closing the Grand Junction for four years ($20 million) saves $100 million in project costs, that seems like a pretty easy analysis (especially if you can then leverage that time to rebuild the Grand Junction so that it can reopen with passenger service from the Worcester Line to Kendall Square, reducing traffic demand crossing the river).

This is the same sort of calculation the T made with the shutdowns of the rapid transit lines for major work. We could get spend $100 million getting this done piecemeal on weekends over the next 5 years, or we could get it done for $50 million all at once given economies of scale, and spend $20 million on buses. There is some temporary pain, but the project gets done faster and costs less. Seems like an easy call.

We can even look over at highways for this. Did shutting down the Sumner Tunnel for weeks on end (and weekends) suck somewhat bigly? Yes. Was it better than doing piecemeal closures over years that would cost way more in the long run? Probably, yes, as well.

It's all cost-benefit analyses which MassDOT and the T seems to be able to do for some projects (Sumner, rapid transit) but not others. They should. And if they do, an additional suggestion would be to cost/benefit the following:

Take the viaduct down all at once, rather than working around the Worcester Line, the Grand Junction, and a bunch of temporary structure to keep some traffic flowing at all times. Do it like the Sumner. Route three lanes of the Turnpike onto Soldiers Field Road and the Paul Dudley White bike path, killing off Soldiers Field Road, on the Saturday before July 4 (since Storrow is closed for much of the next week anyway). BU is out of session, their dorms nearby are closed. Build a temporary station for the Worcester Line in the rail yard, with buses providing service to Back Bay and South Station and a walking connection to the B Line (potentially even a spur down Malvern Street from Packard's Corner, which could be useful in the long run). The buses could use bus lanes to access bypass backups.

Then start hacking away at the viaduct 24/7. Use the rail tracks for gondola cars to haul away the debris (they're already using the yard nearby for construction materials). Have a team of bulldozers and jackhammers and welders cutting and torching the viaduct apart. I'd guess that by late July, the viaduct would be gone, the Worcester Line rebuilt, a new Grand Junction bridge in place and the Turnpike back in business.

Would that month be an utter, epic shitshow? Oh, yeah. But if it saved $500 million getting it all done at once and getting it done years faster, it would probably be well worth the shit.

n/t

While they have the tracks closed they can use that time to make caissons, or footing for the columns to support the to be (properly) widened Dudley White sidewalk and bike path, because I don’t imagine we can cantilever with what we have now.

The bridge that connects Boston to Cambridge is only one of three bridges in the world where a boat can sail under a train driving under a car driving under an airplane. The other two bridges are the Steel Bridge across the Willamette River in Portland, Oregon, and the 25 de Abril Bridge in Lisbon, Portugal,

This is like tearing down the Bunker Hill Monument! /s