A crackdown has reined in T employees' absenteeism and overtime, containing the city transportation agency's costs in the first third of 2016, according to a new report to be released Monday.

The aggressive campaign to train managers and institute a strict new time-off policy in place since January has paid off, MBTA Chief Administrator Brian Shortsleeve will tell the T’s oversight board at its Monday meeting.

“We had a big problem with absenteeism and the T had a pervasive culture that lacked accountability,” Shortsleeve said in an interview Sunday, adding, “I think the results you’ve seen in the last 120 days indicate that we’re on the right track.”

Overtime costs are down by an average of 27.5 percent per day compared to the daily average last year, the report says. In the first third of this year, the T paid $112,000 per day in overtime, compared with $154,000 per day on average last year.

RELATED: T plans to overhaul overtime for workers

Absenteeism among employees who drive trains and buses is down 33.5 percent over last year’s average, and the average number of dropped trips per day on buses is down 40 percent to 93, according to the report.

Absenteeism and overtime are related problems, Shortsleeve said. When an employee is out, someone else needs to be paid overtime to cover their shift, and costs go up.

Much of the reduction has come from increasing the burden on employees looking for days off – among them having managers sign off on requests directly, requiring doctor’s notes as proof for sick days, and keeping a close watch on overtime spending month-to-month. More than 900 managers have gone through a new time-off training program, he said.

“If folks are out on (family and medical leave) or are out for the right reasons, that we understand,” Shortsleeve said. “For folks that may be historically abusing the system, that’s not going to happen anymore.”

For now, Shortsleeve said, the T is on track to reach its goal of cutting overtime expenses by 25 percent in 2016. The T paid $56.3 million in overtime in 2015.

RELATED: Highest-paid T employee made $315,000 in 2015

He said the plan is to invest savings back into repairing and replacing the old and worn equipment on the aging system, chipping away at its $7 billion state of good repair backlog.

The T also has plans to work with a third-party to manage time-off requests and is “very close to signing a contract,” he said.

All of this comes after audits of the system this year have identified issues with employee management, and after news emerged that a track maintenance worker’s pay had been padded with 2,600 hours of overtime in 2015.

James O'Brien, president of the Boston Carmen's Union, has repeatedly pointed to what he calls understaffing at the T as a cause for overtime spending.

T employees have not been accused of breaking the law, and the audits have found no evidence of fraud.

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Transportation Secretary Stephanie Pollack addressed the management policy update briefly in a Sunday morning interview with WBZ's Jon Keller.

“We weren’t managing our workforce and our workforce was taking advantage of us,” Pollack said. “And that’s changed.”