This week, the Orange Line was operating at full speed across the entire line for the first time in about 15 years. On Friday, state officials visited Haymarket Station to celebrate the end of all slow zones on the line.

“I’m really proud of the work of the team that’s been done to eliminate these slow zones on the Orange Line,” said Gov. Maura Healey. “And I’m really grateful to the riders.”

When the MBTA announced its Track Improvement Plan last year, the Orange Line had 44 slow zones in place. The agency suspended service on portions of the line for days at a time — and in some cases multiple weeks — to allow workers to replace rails and ties.

“The track improvement plan has been incredibly disruptive to riders and incredibly important,” said Kate Dineen, president and CEO of the nonprofit A Better City, which advocates for public transit. “Taking a step back, I think that shows that the short term pain is worth that long-term gain.”

The data show service has already improved.

This week, Orange Line trains operated at an average speed of just over 17 mph, about 3 mph faster than this time last year, according to Transit Matters’ dashboards. The number of daily round trips has also increased. This week, the Orange Line averaged 154 round trips each day, compared to 118 a year ago.

MBTA General Manager Phil Eng said Friday that riders can expect more frequent trains in the coming months. When he joined the agency in spring 2023, he said there was a 12-minute wait time between trains on his regular commute from Forest Hills. Come December, he said that should be down to 6 minutes.

“Under general manager Eng’s leadership, the track improvement plan is delivering real results for riders and for the economy,” Dineen said. “And perhaps most importantly, T leadership is beginning to do what we once thought was impossible — they are restoring the public trust.”