Aéroport Charles de Gaulle 1 is one of two railway stations at Charles de Gaulle Airport, the primary airport for the Paris region and the largest in France. The station is served by RER B (a hybrid suburban commuter and rapid transit line that offers services to Paris) and CDGVAL (a free rail shuttle service around the airport grounds). Despite being named after Terminal 1, the station is actually located relatively far from the terminal, but it can be accessed with a short ride on the CDGVAL. Terminal 3 can also be accessed from this station by a five-minute walk on a pathway. The station is located inside Roissypôle, a development that includes office buildings (including the headquarters of Air France), shopping areas, hotels, and the primary bus station for the airport. Because of its location, the station is named Terminal 3 Roissypôle on maps of the CDGVAL system. The station opened on 30 May 1976, two years after the opening of the airport, as the northern terminal of the SNCF's "Roissy Rail" project (Roissy was the original name of the airport) which would connect the station to Gare du Nord in Paris with trains departing every 15 minutes and making the trip in 19 minutes. Like Terminal 1, the station is built with concrete in the brutalist architecture style, designed by Paul Andreu. Once passengers arrived at the station, they were shuttled to the terminal on a bus. In December 1981, the Roissy Rail line became part of the RER B, a line of the Réseau Express Régional (RER), a hybrid suburban commuter and rapid transit system serving Paris and its Île-de-France suburbs. The airport began a major expansion project in the 1980s, with the first section of Terminal 2 opening in 1982. The shuttle bus system was reconfigured to take passengers between the rail station and the new terminal area. Over the coming years, the shuttle bus system began to experience severe delays as road traffic became congested around the increasingly busy airport.