Boston's Central Artery/Tunnel Project, a 7.8 mile system of bridges and underground highways and ramps, is the most expensive public works project ever undertaken in the United States. The original cost estimate of $2.6 billion has already been exceeded by $12 billion, and the project will not be completed until 2005, seven years late. The Massachusetts Turnpike Authority (MTA), the public steward of the project, requested that the National Research Council carry out an independent assessment of the project's management and contract administration practices, with a focus on the present situation and measures that should be taken to bring the project to a successful conclusion. This report presents the committee's findings and recommendations pertaining to cost, scheduling, and transitioning from the current organization dominated by consultants to an operations organization composed largely of full-time MTA staff. The report recommends that MTA establish an external, independent, peer-review program to address technical and management issues until the transition to operations and maintenance is complete; begin a media campaign now to teach drivers how to use the new system safely; and develop, immediately implement, and maintain a comprehensive security program.