As part of a yearslong study about improving the commuter rail , transit officials are considering linking the Newburyport/Rockport commuter lines with the Fitchburg Line, somewhere just north of North Station. That would create a long, single through-route linking North Shore cities such as Salem, Lynn, and Chelsea with Cambridge, Waltham, and points further west.

But another tie-in — this one running east-to-west — appears to be gaining traction at the state Department of Transportation.

There’s been a lot of talk over the years about connecting the commuter rail networks on either side of Boston through the so-called North-South Rail Link, allowing passengers to travel from, say, Lowell to Providence.


The Newburyport and Rockport lines merge in Beverly and run on the same set of tracks toward Boston.

State transit planner Scott Hamwey stressed the idea is “merely a concept” and is one among many as officials consider adjustments to the rail system that would serve more riders with more frequent service.

Even if the east-west connection eventually becomes reality, most trains would still travel on their respective lines into North Station. The T would instead add new routes that would bypass North Station altogether, which would allow the agency to increase service without clogging up already-busy North Station, Hamwey said.

“Under this concept, all existing trips on each line would continue to terminate at North Station,” Hamwey said in a statement. “But, since capacity at North Station becomes a limiting factor in adding more peak period service, some trips would avoid the downtown terminal altogether.”

The proposal stands out because it would create a commuter rail service that doesn’t end at either North or South Station and would allow riders to commute to employment areas outside downtown Boston.

For example, Transportation Secretary Stephanie Pollack said in public remarks this fall, someone on the North Shore could commute to Kendall or Harvard Square by taking the east-west line to Porter Square, a stop on the Fitchburg line, and then switch to the Red Line for the final ride into work.


Commuter rail platforms could also be added at stations such as Wonderland or Sullivan Square to allow train riders to switch to local subways.

“The idea of better connections means that more people who aren’t riders today could become them,” Pollack said in October. Adopting a similar philosophy across the entire commuter rail, she noted, could prove more cost-effective than the North-South Rail Link.

Hamwey’s team is considering six different versions of future commuter rail service, two of which would use the big east-west line. Another, meanwhile, features that fabled North-South tunnel.

That idea would create connections for far more train lines and address the traffic issues at North and South stations by letting trains run through the city instead. The route the state is considering for the rail link would cost about $9.5 billion, officials said at a meeting earlier this month.

Adam Vaccaro can be reached at adam.vaccaro@globe.com. Follow him on Twitter at @adamtvaccaro.