President Donald Trump announced on July 30 a $22.5 billion expansion and modernization plan for Washington Dulles International Airport. The project includes a new hotel, an additional automated train line and a central pedestrian corridor connecting the airport’s terminals and concourses.

One of the most closely watched elements of the plan is the proposed phaseout of Dulles’ distinctive “mobile lounges,” which transport passengers between the terminal and aircraft concourses.

Trump said the airport’s current transportation system is inconvenient because passengers are frequently required to transfer between mobile lounges and trains. Dulles is the only major U.S. airport that continues to operate this type of passenger transportation system.

The mobile lounges have been in service since Dulles opened in 1962. The system was developed as part of Finnish-American architect Eero Saarinen’s original airport design. It was intended to reduce the distance passengers had to walk between the terminal and their gates while allowing greater flexibility in the use of airport facilities and land.

As air travel evolved, however, other airports that experimented with similar vehicles abandoned them because of operational inefficiencies. Experts say the Dulles fleet no longer receives technical support from its original manufacturers, consumes approximately 260,000 gallons of diesel fuel annually and contributes to some flight delays.

The system has also faced safety concerns. On November 10, 2025, a mobile lounge traveling from Concourse D to the main terminal was involved in a collision that injured more than 10 passengers and damaged part of the terminal. A previous investigation by an NBC-owned news outlet found that the vehicles had been involved in at least 16 accidents since 2007.

Under the modernization plan, pedestrian connections and an expanded automated train system are expected to gradually replace the aging vehicles, improving passenger convenience, operational efficiency and safety.