For years, the Baker administration sought to tackle the MBTA’s perennial budget shortfalls by forcing the agency to rein in its spending. In the late 2010s, the T cut hundreds of millions of dollars in spending and hundreds of positions from its workforce. But that ultimately led federal investigators to warn in 2022 that the agency’s staffing shortages contributed to serious safety problems on the system.

It’s been a very different spending story lately.

T officials will request final approval this week on a budget that would ramp up spending considerably once again, extending a years-long hiring and investment spree intended to put the darkest days of slow zones and runaway trains in the past. As has become the new normal, the MBTA would lean heavily on state dollars to make the growth — more than $1 billion over a five-year span — possible.

The $3.4 billion budget, an increase of nearly $300 million over the current year, makes some observers squeamish. Jim Stergios, executive director of the Pioneer Institute, called it “bloated.” But to the group that represents cities and towns who help fund the T, transit leaders are simply catching up with what it actually costs to run the system that the region needs.

“Today’s investments are a direct response to years of deferred maintenance and staffing shortages—conditions that worsened under an austerity-driven approach extending from 2016 to 2022,” the MBTA Advisory Board wrote in its endorsement of the budget proposal.

“Such investments have paid off,” the group declared, recapping the elimination of subway slow zones, more frequent trips in the urban core, and an ongoing project to upgrade signal systems.

After accounting for some mid-year spending controls, the year-over-year budget growth would be a bit more than 6 percent, well above the rate of inflation. Mary Ann O’Hara, the T’s budget chief, pitched the plan as “a deliberate moderation of spending” after several years of double-digit growth driven by the landmark 2022 federal safety investigation into the T.

Most of the new dollars would go toward the final year of Keolis’s contract to run the commuter rail system or toward wages, with T leaders pushing to add another 550 employees.