Inside the electricity substation on the Union Square branch of the Green Line extension. (Photo courtesy of MBTA)

THE MBTA extended until the end of next year the contract of the manager overseeing the Green Line extension, giving him time to wrap up work on the project.

During a recent appearance on The Codcast, John Dalton said his original five-year contract was nearing its expiration date and he needed an extension to see the project through to the end. He also expressed interest in staying on at the T to work on another project after the Green Line extension is completed.

A T spokesperson on Friday confirmed that Dalton’s contract has been extended until the end of 2022 under the same terms – base pay of $299,000 along with eligibility for an “annual success bonus” of an extra 16 percent. Toward the end of next year, the spokesperson said, the T and Dalton will probably discuss whether he stays on beyond 2022 and what role he might play at the agency.

Dalton’s contract makes him the highest-paid employee at the MBTA.

Dalton was recruited from Chicago at a time when the MBTA was embarrassed by cost overruns that sent the estimated cost of the Green Line extension from $2 billion to $3 billion. After T officials withg the help of consultants pared back the cost to $2.3 billion, Dalton was brought in to build a team capable of carrying the project through to completion.

The Green Line extension appears to be coming in under its budget although it is slightly delayed – the branch of the Green Line running to Union Square in Somerville is expected to open next month and the Medford branch is scheduled to open in May.

Bruce Mohl oversees the production of content and edits reports, along with carrying out his own reporting with a particular focus on transportation, energy, and climate issues. He previously worked...