Plans for an airport rail link from the central business district of Stockholm and the airport was launched in the early 1980s. The goal was to reduce road congestion and emissions while allowing Arlanda to keep increasing passenger numbers. The Swedish Rail Administration made a specific plan in the late 1980s which involved the construction of a branch from the existing East Coast Line. This resulted in a project plan which was launched in 1990, which specifically suggested Rosersberg and Odensala as the intersections with the existing line. The political decision to build the line was taken in 1993. Estimates at the time gave a ridership of 5.1 million passengers per year in 2005.