You can take the commuter train out bound from Boston, off hours. That would be Am and not pm rush hour, at least week days. Get you to Kingston. Pedal from there? Miles Standish SF is a good stop. There is one bridge you can " ride" across. 2 ' high, traffic very close with trucks pushing a lot of air coming at you. Took me a bit. Then the service road after that. Just a thought. Just read the rules, regs and hours carefully for the MBTA commuter line.