Extra tall double decker 60' articulated buses for route 28 extended to Malden
Seattle has some
double decker buses.
Unfortunately, those buses apparently have somewhat limited interior headroom. That's presumably a result of trying to keep the height within the
typical 13.5' to 14' limit of state laws; the ADA regulations related to white cane users choose to care about people up to 6' 8" tall, and having two levels able to accomodate 6' 8" people would require 13' 4" plus a bit of extra headroom, ground clearance, and floor / ceiling space.
The big issue with building a bus 16' or 17' or 18' tall would be if the route it operates on needs to pass underneath bridges. If you can find a route that avoids passing under bridges that don't have generous clearance, then there should be no physical problem with a tall bus, although shipping it from the factory to where it gets used might be a challenge.
In looking at Google Street View images of some random parts of the MBTA's route 28, I didn't see anything south of Dudley St that would preclude an extra tall bus; the bus goes above the Fairmount Line. The busways at Dudley Station and Ruggles Station might need some changes to deal with extra tall buses.
If the route was continued northwards above the Amtrak / commuter rail tracks from Ruggles Station to Mass Ave, and then along Mass Ave to Vassar St and somehow to Lechmere, I don't think there any any obvious obstacles there unless the new Lechmere Viaduct ends up being too low.
If a bridge gets built from near Lechmere Station to Inner Belt Road, hopefully that could be above everything else.
I suspect passing under I-93 on Cambridge St to get to the existing Sullivan Station busway would be problematic. However, if the unused western tracks at Sullivan are converted to Green Line, perhaps there would be some way to share the underpasses under Mystic Ave and Broadway / Maffa Way between Green Line and tall buses; the tall bus wouldn't be any taller than the bilevel commuter rail cars, although trying to have Green Line overhead wire share the space with a tall bus might be problematic. But a ramp up to Cambridge St at the south end of the potential Green Line tracks at Sullivan would at least be to the west of I-93 and potentially solve the clearance problems passing underneath I-93.
Sweetser Circle to Malden Orange Line seems to avoid overpasses as long as the bus stays on the east side of the tracks at the Malden Orange Line station.
I'm not aware of anyone ever having built an articulated double decker bus, which might be the real challenge. And it's not clear that there's much value in a double decker articulated bus; while it would offer a good view from the upper level, the staircase(s) waste a significant amount of space (although that would probably be a smaller percentage of the lower level with a longer bus unless that's used as an opportunity to add a second staircase where typical double deckers might only have one staircase). Just running frequent 60' single level low floor buses probably provides adequate capacity.
