IAD continues to rely on Concourse C/D and the mobile lounge surface vehicle system. If the Tier 2 projects are not implemented, IAD will provide a diminishing quality of service to an increasing number of passengers. Concourse C/D presently provides insufficient space and amenities to airlines and their passengers. The aging mobile lounge system will continue to operate, creating surface traffic congestion on the airfield and operational delays. The lounges are diesel powered and contribute air emissions. In addition, the existing mobile lounges and planemates are no longer being manufactured. Contractors can no longer be found to perform the major rehabilitations that would be required to keep this out-dated equipment operating past 2010. The mobile lounge inefficiencies will be magnified as passenger growth continues, and flight departures and arrivals will be increasingly subjected to delays associated with the inability to efficiently transport passengers between their aircraft gates and the Main Terminal. Delays associated with inefficient passenger transport will cause subsequent aircraft arrivals to be delayed, causing aircraft to wait in remote areas of the airfield with their engines idling while awaiting a gate. At-grade transfer of baggage by tug and cart between the concourses and the Main Terminal will also continue with the corresponding surface/ground congestion and air emissions. IAD operations will continue to increase with more passengers, more aircraft, and more automobile traffic. The environmental benefits, efficiencies and service level of high-volume modern systems will not be realized.

United Airlines, in consultation with the Authority, conducted an assessment in early to mid1999 to determine if existing Concourse C/D could be modified to meet (1) United’s then-current needs, and/or (2) United’s future needs at IAD. In summary, the assessment determined that modifying existing Concourse C/D to meet even United’s 1999 needs was physically and operationally impractical, as well as cost-prohibitive given the relative degree of improvements that could be achieved.