DART Work continues on the Dallas Area Rapid Transit (DART) Silver Line Regional Rail project with the start of construction on the Josey Lane bridge in Carrollton. Photo courtesy of DART For the initial bridge construction, a large diameter hole is drilled into the ground and filled with steel rebar and concrete for each bridge pier. With depths ranging from 42′ to 49′, each hole is drilled into the bedrock for strength and stability. With a diameter of 54″, each pier footer is filled with up to 30 cubic yards of concrete, which is over 6,000 gallons. Photo courtesy of DART The Silver Line Regional Rail Project’s primary purpose is to provide passenger rail connections and service that will improve mobility, accessibility and system linkages to major employment, population and activity centers in the northern part of the DART Service Area.