Washington, D.C.’s Metrorail system is eyeing a major bridge and tunnel upgrade for its first use of construction manager at-risk (CMAR) project delivery.

Located within a nearly 50-year-old, 6,000-ft-long corridor between the Yellow Line’s Pentagon and L’Enfant Plaza stations, the project includes repairs and fire-suppression system upgrades for a 3,000-ft-long, box-girder bridge spanning the Potomac River.

It also includes addressing decades-long water infiltration issues that have eroded connecting steel-lined tunnels.

Responses to the solicitation are due in April. Construction is expected to begin in fall 2022.

Laura K. Mason, the Washington Metropolitan Area Transit Authority's executive vice president of capital program delivery, said in a  March 5 statement that the agency has "an aggressive capital campaign to rehabilitate and repair elevated structures, and the Yellow Line bridge is the top structural priority."

Mason added that moving rapidly on the bridge and tunnel project "will allow Metro to utilize [CMAR] on future projects to more quickly address critical safety needs of other elevated structure.

WMATA, Metrorail's operator, says 31 of its nearly 150 elevated track and rail station structures are in need of rehabilitation or repair.