Breakthrough at Bethesda Metro Station

Clark’s expertise in mass transit began in 1975 with the construction of the Judiciary Square and Gallery Place Stations – the birthplace of the Washington Metropolitan Area Transit Authority (WMATA) stations’ signature coffered panels. Fifty years later, Clark continues to modernize and maintain the vital infrastructure that moves greater Washington, most recently at the Bethesda Station South Mezzanine project.

The new mezzanine will connect the existing WMATA Metro Bethesda Station to the Maryland Transit Authority’s (MTA) new Purple Line light rail through an underground bridge, expanding accessibility to two major public transportation providers for residents. To make way for the bridge, the Clark Civil team cleared 148,000 pounds of concrete to expose a tunnel that had remained sealed for five decades. Crucially, this complex demolition also needed to be completed within a tight 44-hour weekend shutdown, known as a rail service adjustment, to be ready to re-open in full-functioning capacity by 5:00 a.m. Monday.

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During demolition, crews had to be mindful of the surrounding panels from the station’s initial construction in the 1970s. With only a few inches of tolerance, the team leveraged a remote-controlled robot to precisely and carefully demolish specific areas without  jeopardizing the integrity of the adjacent panels. This technology proved essential when removing the bottom four feet of obstructed concrete, which was wedged between the safety crash deck and the historic infrastructure nestled behind the panels.

Despite the challenging time and preservation constraints, crews finished safely and successfully, welcoming passengers back on time for the Monday morning commute. Now, the team prepares for steel erection for the connecting passenger bridge, which will be erected in July. The new South Mezzanine is expected to be completed in May 2027.