The $40 Million Tunnel
To include the Capital Crescent Trail with the Purple Line through a tunnel under Wisconsin Avenue at the Bethesda-Chevy Chase border would be more costly than re-routing the trail at the street level, but the street-level route could be more dangerous.
Members of the Montgomery County Planning Board met with staff members of the Maryland Transit Authority on Thursday morning to examine the tunnel that runs under Wisconsin Avenue at the Bethesda-Chevy Chase line.
Currently, the route of the Capital Crescent Trail runs through the tunnel, and the Purple Line light rail (on which construction is slated to begin as early as 2015, according to the MTA) is planned to run through the tunnel. If the trail is to remain in the tunnel with the Purple Line, the trail will be reconstructed in a passageway that will run above the light rail, MTA staff members say. That could cost around 43 percent of $103 million, or around $40 million, The Washington Post has reported.
Such a configuration will require excavation of the tunnel, and many columns that support the Apex Building and Air Rights Center (which rise above the tunnel at its western and eastern ends, respectively) will need to be strengthened. Excavation and column strengthening will be expensive, according to MTA engineers.
While the Purple Line will be built with state and federal funds, reconstruction of the Capital Crescent Trail alongside the Purple Line must be funded primarily by the county, says Michael D. Madden, project manager for the Purple Line. The county planning board will meet on Thursday, Nov. 17, to discuss whether to route the Capital Crescent Trail through the tunnel or at the street level to cross Wisconsin Avenue.
Opponents of the Purple Line say that crossing the Capital Crescent Trail at the street level will be very dangerous, and will destroy the continuity of the trail.