Along the Green Line Extension, which extended the trolley line north of Lechmere via two branches to Union Square and Medford, slow zones are making for speeds as slow as 3 miles per hour for more than a cumulative mile, according to the Boston Globe.
The reason for the new slow zones — 11 on the Medford branch and three on the Union Square branch — is that the T found the rails were too close together at many spots, the Globe reported.
"Earlier this month, MBTA track inspectors performed a regularly schedule geometry scan of the Green Line Extension tracks, and found some areas where the width between the rails was slightly out of the limits of the regular track standards," an MBTA spokesman told NBC10 Boston in an email. "The MBTA is working to determine the cause of these aberrations in the track gauge."
Get Boston local news, weather forecasts, lifestyle and entertainment stories to your inbox. Sign up for NBC Boston’s newsletters.
The Union Square branch opened in March 2022, and the Medford branch of the project opened in December of 2022. The project represented a $2.3 billion investment to extend the Green Line northward.
Meanwhile, the Union Square branch of the Green Line Extension is suspended through Oct. 12, as MassDOT crews work on the Route 28 Squires Bridge. An MBTA spokesperson told the Globe that the agency hopes to have the slow zones on that branch eliminated by the time service returns.
As for the 11 speed restrictions on the Medford branch, the Globe reported that work began last week to get things up to speed.
According to the MBTA's online dashboard, there were 244 total speed restrictions systemwide as of Tuesday. 83 of those were on the Green Line.
From Aug. 28 through Sept. 26, the MBTA opened 33 speed restrictions, while closing 19, meaning an overall increase of 14 slow zones in a month's time.
