Dulles Airport Tunnels

New landside, airside facilities enhance travel and accommodate growth

Metropolitan Washington Airports Authority | United States | 2001-2008

58,000 feet of tunnels

Automated people-mover system

US$3.4 billion development program


  • The Dulles Development Program needed a network of tunnels for new, upgraded systems: an automated people mover (APM), a pedestrian tunnel, utility tunnels, underground baggage conveyors, and roads for airport tugs.
  • Adjacent airport operations and construction were successfully performed concurrently requiring multistaged construction sequencing.
  • Following the events of September 11, 2001, construction plans were reevaluated to reflect affected passenger figures and enhanced security requirements.
  • A second project phase was initiated following a reassessment of infrastructure requirements. Many specialist subconsultants were involved to complete the design of a pedestrian tunnel extension and other tunnels, including a covered baggage conveyor system with all necessary linkages.


  • Detail design and design management was provided for the APM, baggage, and tug tunnels. Our scope included detailed design for the tunnels and associated structures, mechanical/electrical systems, ventilation systems, and the vehicle maintenance facility.
  • We led a team, including ten subconsultants, to finish the design of the pedestrian tunnel extension—the 2,800-foot-long, twin-35-foot-diameter, tunnel-boring-machine tunnels that link to a baggage conveyor tunnel; and a 2,400-foot-long extension of the west APM twin tunnels.
  • Tunnel designs were developed with special attention to fire and life safety.


  • 58,000 feet of tunnels bored, ranging from 18-foot diameters created by tunnel-boring machines, to 40-foot-wide New Austrian Tunneling Method caverns.
  • Ground conditions consisted of siltstone overlaid by weathered rock and residual soils.
  • Tunnels were constructed in the airport operating area under taxiways that remained operational throughout.
  • Eight stations and a maintenance facility for the APMs were constructed.

Project numbers

Phase 1: US$450 million construction cost
Phase 2: US$300 million construction cost
1,875-foot-long, 40-foot-wide, pedestrian-tunnel extension
700-foot-long, cut-and-cover baggage-conveyor tunnel

How we can help you

If you have a problem that needs to be solved, please get in touch.

Contact Us