AAI conducted core drilling for geological characterization as part of the Interstate 70 Twin Tunnels Widening Project in 2012 on behalf of Parsons Transportation Group Inc. and Yeh & Associates, Inc. of Denver. The project involved the widening of both the east and west tunnel bores of an active interstate highway from two to three lanes each. AAI drilled three rings of NXBWL core holes ranging from 20 to 60 feet deep inside the active eastbound tunnel. Traffic control was coordinated with the Colorado Department of Transportation. Later in the project, AAI cored one 250 ft long horizontal NQ hole in the pillar separating the parallel tunnels. Drilling was conducted from the median of the highway. A second 250 ft long horizontal hole was cored from a talus slope south of the tunnels. Two 60 ft deep holes were cored into the roof from a flatbed semi-trailer inside the eastbound tunnel and a third 60 ft downhole was cored outside the tunnels. The drilling campaign was completed successfully and delivered key geologic data for design of the tunnels. AAI returned in 2014 to drill and case an inclined hole for cable routing in the westbound tunnel.