Report: Overhaul Needed to Fix Rail Travel to South Shore A map from the reports shows recommended upgrades. TransitMatters 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.