Has anyone really studied Newport as part of intrastate service, instead of part of a SCR extension? I can't imagine you can get across Narragansett Bay to Quonset, or to The E. Bay Bike Path running through Bristol to E Prov. That path is too disconnected on the providence end to even contemplate.
(Also, when was the last use of the street running track on Allens Ave/1A?)
I don't know of any formal studies. The only way I can imagine a Newport-Providence service is one that runs via Fall River, Taunton, and Attleboro. And the only way I can imagine
that working is if there are timed transfers to high-speed Boston service at either Taunton or Attleboro,
and if the Newport-Providence service itself is electrified and high-speed as much as possible. Thus you'd be able to capture local commuters to Fall River and Taunton, and be able to offer a transfer service for Newport commuters to Boston, and be able to capture some Fall River-Providence (and maybe Taunton-Providence) commuters. Pull all those together, and you might be able to stitch together a ridership coalition strong enough to make it viable.
(If all Boston-Fall River trains were rerouted to New Bedford, and Fall River were served by Providence trains with a transfer at Taunton, you might be able to swing high enough frequencies on both to make them effective. Maaaaaaybe.)
But yeah -- Newport-Providence via Taunton is looooooooooong. Like, 55 miles looooooong. (For reference, Boston-Wickford Junction is 57 miles as the crow flies.)
RIPTA's 60 bus pings back and forth between Newport and Providence from early morning late into the night, at 15 minute headways (!) during peak, 30 min off-peak, and 60 min until well after midnight. Total journey time is about 80 minutes. After local service on Aquidneck Island, it runs local through Bristol (with stop at Roger Williams University), Warren and part of Barrington, before expressing to Providence. So, a rail route might be able to soak up some of that, and presumably there would be
some ridership from Fall River and Taunton.
RIPTA's 14 runs a commuter service via the West Bay at much lower frequencies. Its travel times vary depending on number of stops -- anywhere from 50 minutes to 80 minutes.
Driving time of course is maybe 45 to 60 minutes. And
seasonal ferry service is timetabled at 60 minutes.
Could a train beat those buses or driving? I mean, maybe? But, it's a looooong way round. I think the best hope is the coalition outlined above, where Newport-Providence is only a portion of the target market. (Maybe supplemented by some sort of Cape Codder service direct from Boston.)
Don't get me wrong -- I'd love to see it happen. But a lot of pieces need to be put in place first.