Transportation Secretary Elaine Chao joined K. Jane Williams – acting administrator for the Federal Transit Administration – Massachusetts Gov. Charlie Baker plus other state local officials at a June 25 ceremony to officially release $225 million in federal grant money for the Massachusetts Bay Transportation Authority Green Line Extension or “GLX” light rail project.

The project – expected to be fully completed by January 2022 – includes seven new light rail stations, replacement or rehabilitation of eight bridges, and a new pedestrian/bike path.

The GLX – which will serve about 75,000 residents – is expected to generate approximately 40,000 new transit trips a day, improving access to jobs and opportunities in Boston as well as the communities of Somerville and Medford, home to Tufts University.

This grant also represents the second installment of funding for the GLX after FTA signed a $996 million full funding grant agreement for the $2.3 billion project.

Once completed, trains will operate every five to six minutes in the peak periods, providing fast and efficient service along the 4.7-mile light rail line extension from Cambridge to Medford to downtown Boston, noted Stephani Pollack, Massachusetts’s Transportation Secretary and CEO.

“Today’s groundbreaking is another milestone in the concerted efforts it took in making GLX a reality,” she said in a statement. “Nearly two years ago, the Baker-Polito Administration hit the pause button to address GLX cost overruns, found ways to reduce the original design cost by one billion dollars, and led the effort to redesign the project.”

“The Green Line Extension will improve access to education, housing and job opportunities across the entire MTBA system,” noted Gov. Baker in a statement. “Our administration is grateful for the collaboration and support we have received from Secretary Chao and all partners at the federal, state and local level to reach this milestone and begin a project that will have a transformational impact on this region of the Commonwealth by accommodating riders and spurring economic growth.”

In November, the MBTA’s fiscal and management control board voted unanimously to award the design and construction contract to GLX Constructors, which is comprised of Fluor Enterprises, Middlesex Corp., Herzog Contracting Corp., and Balfour Beatty Infrastructure.

The total project cost, again approximately $2.3 billion, includes other project components such as real estate, professional services, contingency, and procurement of 24 new trolleys to augment the existing Green Line fleet, the first of which is anticipated to enter service in fall 2018 with all cars anticipated to be complete by early 2019.

Design and pre-construction work, such as vegetation clearing and utility location along the right of way, is currently underway. MBTA said, with heavy construction expected to start this fall with the project scheduled to enter the testing phase in late 2020 and the extension operational in late 2021.

Photo: MBTA