A transit advocate says supporters of Cape Cod commuter rail should get behind a proposal to build capacity on the tracks farther north.
Jarred Johnson, executive director of the group TransitMatters, said a bottleneck of single track exists between Braintree and Dorchester.
“There's a really pretty severe limit on the number of trains that can go back and forth in both directions,” he said. “And adding in trains from Fall River and New Bedford is going to exacerbate that issue.”
He said capacity on that track is a bigger impediment to train service south of Boston than the capacity issues at South Station.
“There's potentially a scenario in which trains from five different destinations are converging on that single-track section,” he said. “So that, really … more so than capacity of South Station, is the real limiter to being able to have much more frequent service on South Coast Rail.”
Plans to build a double track in the Braintree-Quincy-Dorchester area are at a very early stage and have no construction funding, Johnson said.
He said supporters of rail service on the Cape and South Coast have an opportunity to advocate for changes this spring, when the Massachusetts Bay Transportation Authority writes its five-year capital plan.
“This upcoming spring is actually going to be a good opportunity for the state to really start putting their money where their mouth is, in terms of some investments that will help South Coast rail be more successful in the future.”
Johnson said that over the long term, moving South Coast Rail to the Stoughton line, as the state pledged to do, would free up more capacity for Cape Cod.
Other changes would be necessary for Cape Cod commuter rail to become a reality.
Tom Cahir, administrator of the Cape Cod Regional Transit Authority, has said the existing tracks on the Cape can’t handle trains fast enough for commuter rail and would need to be upgraded.
In August, state Rep. Dylan Fernandes of Falmouth and Rep. Kipp Diggs of Barnstable announced that they were filing a bill to require the MBTA to open commuter rail service from South Station to Buzzards Bay — on the mainland side of the canal — within a year of the bill’s passage.
