Midnight Marathon Ride
Show ‘n’ Go (no leader, no organizer): Bike the route of the Boston Marathon in the dark, starting at midnight the night before the race.
https://ridewithgps.com/routes/7498424
You have to figure out logistics on your own — where to start, how to get there, how to get back from the finish.
The route above, posted in 2015 by the ride’s O.G., Greg Hum, starts from the commuter rail station in Southboro.
There’s a private discussion group: https://www.facebook.com/groups/MidnightMarathon/
As of April 16, 2025, this website has not been updated from 2024, but it has some info that is likely still useful: https://www.midnightmarathon.org/