Final design is the last stage of development of a public transportation project. It includes preparation of final construction plans, detailed specifications and cost estimates, bid documents and real estate acquisition. The aforementioned funds were appropriated by Congress in the fiscal year 2001 Transportation Appropriations Act.

The multi-billion project would create a 23.5-mile light rail line running north to south from Northgate, through Downtown Seattle, Southeast Seattle and the cities of Tukwila and SeaTac. The project will consist of 23 stations, four new park-and-ride lots, and one existing lot. The system would operate on existing and new right-of-way, including the existing 1.6 mile Downtown Seattle Transit Tunnel. Sound Transit estimates a total of 156,400 daily riders on by 2020.

The approvals will help address "the serious mobility and congestion challenges facing the region," says Secretary Mineta, adding that the project was one of the first issues he faced at the Department of Transportation. "I am pleased to see that since that time the Congressional delegation in the Seattle region has worked long and hard with all parties to bring the Central Link Light Rail to this approval."