TAUNTON — For the first time in more than a half century, on Monday, residents of Massachusetts’ South Coast communities, including Fall River and New Bedford, began hopping on a commuter rail train to be whisked directly into Boston.

The region hasn’t had a train to Boston since the 1950s, when highways became king. Now, after more than three decades of political promises and $1 billion spent, South Coast Rail is scheduled to open Monday.

The MBTA’s South Coast rail begins service Monday, shuttling riders from Boston’s South Station to Taunton, Fall River and New Bedford. Those three communities were the only “major cities” within 50 miles of Boston that were not serviced by the Commuter Rail — until Monday.