Colin A. Young | GBH

“By shifting from a commuter-focused model to a "regional rail" model, the MBTA's Greenbush, Kingston/Plymouth and Middleborough/Lakeville lines could run trains every 30 minutes, shave 15 minutes off trips into Boston and make public transit a more realistic option for many, a new report suggests.

TransitMatters also said an investment of $630 million could electrify the Old Colony trunk line and its three branches to allow for speeds of up to 100 mph, double-track congested sections like a bottleneck between Dorchester and Braintree that causes scheduling issues, and make adjustments to track alignments at Quincy Center.

With those changes, the lines that have some of the lowest ridership and frequency levels could instead ‘provide frequent, affordable connections from the South Shore communities to Boston's job market and to each other, particularly Brockton and Plymouth,’ the nonprofit advocacy organization that regularly seeks improvements to the transportation system said in its report.”