You can walk as fast as MBTA trains on parts of the Green Line, data shows

SOMERVILLE, Mass. — Commuters can walk just as fast as some MBTA trains along parts of the new Green Line Extension, which opened in 2022, data indicates.

As of Wednesday, there were nine zones on the Medford/Tufts and Union Square branches that had trains operating at a reduced speed as low as 3 miles per hour, the MBTA’s Speed Restrictions Dashboard showed:

Ball Square to Medford/Tufts (eastbound) -- 3 mph over a restricted distance of 0.2 miles
Gilman Square to Magoun Square (eastbound) -- 3 mph over a restricted distance of 0.1 miles
Lechemere to East Somerville (eastbound) -- 3 mph over a restricted distance of 0.1 miles
Medford/Tufts to Ball Square (westbound) -- 3 mph over a restricted distance of 0.2 miles
Ball Square to Magoun Square (westbound) -- 3 mph over a restricted distance of 0.1 miles
Gilman Square to East Sommerville (westbound) -- 3 mph over a restricted distance of 0.2 miles
East Somerville to Lechemere (westbound) -- 3 mph over a restricted distance of 200 feet
Lechemere to Union Square (eastbound) -- 3 mph over a restricted distance of 250 feet
Union Square to Lechemere (westbound) -- 3 mph over a restricted distance of 0.2 miles

For most healthy adults, the average walking speed is about 3 mph, a recent study found.

The MBTA defines a speed restriction as “an area in which trains are required to run at slower-than-normal speeds because of track wear and tear or other problems.”

So what’s behind these speed restrictions? The width between the rails isn’t quite right, MBTA spokesman Joe Pesaturo said in a statement.

“MBTA track inspectors performed a regularly scheduled 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,” Pesaturo said. “With safety a top priority, the current speed restrictions are in place until the defects are addressed during overnight periods on the Medford branch and during the ongoing closure of the Union branch.”

Pesaturo also noted that transit officials are working to determine the cause of these aberrations in the track gauge.

The speed restrictions on the Union branch will be removed before Green Line service resumes on October 14, according to the T. The branch was shut down earlier this month to give crews the chance to do important repair work on the Squires Bridge on Route 28.

As of Wednesday, there were dozens of other Green Line zones with restrictions of 10 mph or less in place, data showed. There were also 83 restrictions totaling 13.25 miles along the entire line.

This is a developing story. Check back for updates as more information becomes available.

Download the FREE Boston 25 News app for breaking news alerts.

Follow Boston 25 News on Facebook and Twitter. | Watch Boston 25 News NOW