River/New Bedford line, which opened Monday, has been in the works for decades and has cost billions. The post 3 things to know about the new rail line connecting southeastern Mass. to Boston appeared first on Boston.

Like all other Commuter Rail trips, the first train Monday morning on the MBTA’s new Fall River/New Bedford line set off with a jolt. But unlike the rest, it was followed by an unfamiliar sound for the early hour: applause.

For the first time in more than a century, residents of Massachusetts' southeastern communities can hop on a commuter rail train and be whisked directly into Boston.