MBTA’s Red Line running at full speed through all stations for the first time in 20 years

For the first time in decades, the Red Line is entirely free of slow zones.

According to the MBTA, it’s been at least 20 years since the busy subway line, running south from Alewife toward Braintree and back again, was last operating at full speed along the length of its more than 22 miles of track and past its nearly two dozen stations.

“I’m proud of the tremendous amount of work we’re accomplishing. The track in these areas of the Red Line is very challenging for crews to be able to access, but our workforce was given the unencumbered time on the track that they needed to finally do the work to completely remove these slow zones,” MBTA General Manager and CEO Phillip Eng said in a statement.

With the removal of the Red Line’s final two slow zones — both located between the Central and Kendall/MIT stations — the Red Line now joins the Blue and Orange Lines in providing riders a full-speed commute into and through the city of Boston.

The remaining slow zones on the Green Line, the last to be seen to as part of Eng’s demonstrably successful Track Improvement Program, will be lifted in the next month, according to the General Manager.

An unrestricted Red Line was made possible after suspending service from Harvard to Broadway through much of last week and between Harvard and JFK/UMass on Sunday. During that time crews replaced 2,230 feet of rail — 970 feet of which required full-depth track replacement — replaced 177 ties and 3,350 plates, and resurfaced and tamped a further 13,800 feet of track.

Crews also used the customer-free space to make repairs to stairways at Kendall/MIT, Park Street, and Downtown Crossing Stations, install security upgrades at Charles/MGH and Park Street Stations, replace the third rail at South Station and the power cable at Kendall/MIT, and make a variety of electrical improvements.

The closures were part of a year-long effort to solve the slow zone problem plaguing the region’s public transit system. When Eng, the former President of the Metropolitan Transportation Authority’s Long Island Rail Road, first started the job as Gov. Maura Healey’s pick to turn around the beleaguered MBTA, there were nearly 200 portions of the system under speed restrictions.

Shortly after assuming the role, and no doubt in part because fixing the problem was required following a Federal Transit Authority Safety Management Inspection of the system, Eng broke the bad news that there would be sporadic system shutdowns through the length of 2024, but promised riders that the inconvenience would result in a better, faster system.

As of Monday, there were just two restrictions left.

“There’s more work to do on the Green Line next month to make the entire subway system slow zone-free, but we’re now well-positioned to efficiently maintain our system for years to come with the goal of providing the safe, reliable service our riders can be proud of,” Eng said.