Dulles International Airport: Automated People Movers
Dulles, VA

Originally designed by Aero Saarinen in 1962, Dulles International Airport's main terminal building was an iconic architectural achievement of aesthetics and function for its era. Functioning over the past 45 years as one of the pre-eminent international airports in the United States, Dulles has experienced an increase in the volume of traffic to more than 60 million passengers annually. This success strained the mobile lounge transportation system to the limits of its capacity to convey passengers around the 10,000 acre airport property. By its very nature, the fleet of 50 vehicles had to compete with aircraft and an array of service vehicles, which presented a logistics challenge. The airport tarmac was congested to the extent that it limited the capacity for Dulles to expand their operations.

In order to keep pace with increased passenger traffic and fleets of new, larger aircraft carrying greater volumes of passengers, Dulles needed to bring more gates and terminal expansions online as demand required them. To accommodate these expansions, the Metropolitan Washington Airports Authority committed $1.4B to create an Automated People Mover (AeroTrain) passenger transportation system below grade. The new AeroTrain system now frees up the airport tarmac and allows for future expansion of the airport for decades to come.

The increased capacity and efficiency of the AeroTrain system will also abbreviate travel time as passengers navigate the airport terminal facilities, clear security and reach their aircraft or ground transportation. The aging fleet of diesel-fueled mobile lounges is being replaced with a high speed electric train which runs the 5 mile course at speeds up to 42 mph. Wait times will average 2 minutes or less, meaning that passengers will take no longer than 72 seconds to get from one APMS to the next.

Providing good indoor air quality for stations below grade and in an extensive tunnel system will directly impact health and quality of life for the travelers and employees who will use it on a daily basis. Demand side ventilation efficiently provides conditioned air which has been processed through gas phase filtration to remove the ambient contaminants common to an aviation facility.

Complicating the mechanical systems design is the fact that numerous HVAC systems interface at the APMS; five separate design teams worked simultaneously on five different components of the overall expansion project. It required an approach which accommodated the various design features and schedules to come together into one cohesive system that would respond to day-to-day requirements as well as extraordinary circumstances, such as a fire or smoke event.

Should such an event occur, a highly complex comprehensive ventilation interface and control system (CViCS), will initiate a series of integrated automatic procedures designed to assist in the evacuation, ventilation and suppression of a train fire. Syska's strategies for fire protection and smoke isolation will allow passengers enough time to exit safely to the outside from the lowest levels.

Many of the innovative components of this project, such as the misting fire/life safety system, have never been used outside of maritime applications in this country. As such, it was a particular challenge to provide an infrastructure support robust enough to meet the challenges while respecting the importance of energy efficiency in ongoing operations and costs.

Ultimately, Syska's designs are being used by MWAA to establish new standards and design guidelines for mechanical, electrical, plumbing and fire protection engineering for aviation facilities going forward. On this project we were privileged to provide a new airport facility that is innovative, safe, and vital to the economic and social needs of the Washington Metropolitan Region.


163,000 sf West Domestic
118,000 sf East Domestic


2010 Honor Award Winner in the Design Category - A
2010 National Finalist for Building/Technology Systems - American Council of Engineering Companies
2009 Honorable Mention, Engineering Excellence Building/Technology Systems - ACEC Metropolitan Washington