Projects

Built as a solution to ease the notorious congestion north of Dallas, the Addison Airport Tunnel enables vehicular traffic to travel under the airport, thereby expanding traffic capacity on the heavily traveled east-west routes between Dallas and Addison. The tunnel was completed in 1999, and at more than 15 years...

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The 3,300-foot long Big Savage Mountain Tunnel was constructed in 1911 as part of the Western Maryland Railroad line. After providing continuous rail service, it was abandoned in 1975. For the next 25 years, failure in the crown and wall of the tunnel developed due to adverse geologic conditions, significant...

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The Metro Gold Line Eastside Extension is a 6-mile-long, dual light rail transit (LRT) alignment that includes 1.7 miles of tunnel, offering the Eastside faster and more convenient access to multiple destinations. The line starts at Union Station in downtown Los Angeles, where it connects with the Pasadena Gold Line...

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Completed in 1953, the Squirrel Hill Tunnel provides a crucial link between Pittsburgh, Pennsylvania, and the city’s eastern suburbs. As business and industry grew in the mid-20th Century, construction of the tunnel helped the city handle traffic from the east. The average daily traffic (ADT) travelling through the tunnel has increased...

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The Virginia Avenue Tunnel is a major railroad tunnel in Washington, D.C., that serves freight trains along the eastern seaboard. The 110-year-old tunnel is in the beginning stages of an expansion and modernization project that will improve freight traffic flow and eliminate a bottleneck that impacts commuter and passenger trains...

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