When the Orange Line was originally constructed in 1977, foundations for the bridges to carry the Silver Line over I-66 to the median of the Dulles Access Road were built up to ground level. These foundations included steel piles that were driven into the ground and capped with concrete. However, detailed records for these original foundations were lost. As a result, engineers asked for the foundations to be inspected by digging around them to determine the condition of each pile under the concrete foundation caps.