How feasible/beneficial would it be to run key bus routes with the highest ridership as overnights from 1-5am like the Owl buses in San Fran? Or even just on Friday-Saturday overnight so people can get home from clubs, bars, work safely without sometimes sketchy Uber and Lyft. The 23, 28, 57, 66, and 1 seem like good candidates and I’d imagine it’d be nice for those employed at these late-running establishments that have to be at them later than anyone else to know there’s a transit option to get home.
For an intelligently run and properly staffed transit system, entirely feasible. For the MBTA at this exact
moment in time - probably impossible due to the driver shortage.
They currently don't have enough drivers to be running the intended level of service and we're seeing service reductions because of it. Adding service at a time few people actually want to work, seems like it's clearly not going to work out from a staffing perspective with their present workforce. Even if you paid better for those shifts - when you don't have enough drivers to go around you're probably just making existing service worse.
Assuming you fix the driver shortage (which is fixable with....money and a bit of time), the difficulty I see is in figuring out how to design the missing routes you need in a way that people actually know they're there and use them.
Routes like you mention are good candidates to run, but they're also of pretty limited utility in a lot of cases without some kind of replacement for links normally made by subway.
For example, the 57. Sure, there is absolutely some ridership just along the corridor, maybe even enough to be consider running it by itself. But a lot is normally looking to go further inbound from Kenmore....via the Green Line that's not running.
I am not overly familiar with the last attempt to do a late night bus system (which I believe tried to basically mimic subway routes to the stop), but I do think that the advent of smartphones/transit apps makes it somewhat more realistic today to get people to use a late night bus route that can stay on the major road corridors and link what needs to be linked/cover the urban core, rather than having to hit each subway station's actual location.
Of course, this would require good communication and marketing....also questionable as a strength of the MBTA at the moment.