Arlanda Express is an airport rail link connecting Stockholm Central Station with the Stockholm Arlanda Airport outside Stockholm, Sweden. Operated by A-Train AB, the trip takes 18 minutes and runs four to six times per hour using seven X3 electric multiple units. The services operate over the East Coast and Arlanda Lines calling at Stockholm Central, Arlanda North and Arlanda South stations. The service was used by 2.7 million passengers in 2007 and by 3.3 million passengers in 2012. Planning of the airport link started in the 1980s. In 1993 the Government of Sweden issued a tender for a public–private partnership (PPP) to build the Arlanda Line. The construction of the line was subsidized with a combination of some state grants and large state loans. The successful tenderer would receive a monopoly on traffic between the airport and Stockholm until 2040. The line and the services were inaugurated on 25 November 1999. The PPP contract has since been criticized for being unclear, uneconomical for the state and leading to a low utilization of the service as ticket prices are very expensive at 300 SEK (around 30 EUR) for an adult single ticket on the very short journey. The railroad is owned by two Australian pension funds and partly (37.5%) by the Gingko Tree Investment Ltd, a subsidiary of Chinese State Administration of Foreign Exchange. Service The Arlanda Express connects the city center of Stockholm, at Stockholm Central, to Stockholm Arlanda Airport. At the airport, the train serves two stations: Arlanda South, which serves terminals 2, 3 and 4, and Arlanda North, which serves terminal 5. From Stockholm to Rosersberg, the train follows the East Coast Line, and from there to the airport, the Arlanda Line. The train operates four times per hour, increasing to six times per hour during rush hour. , the standard price for a one-way ticket is SEK 295, although discounts are offered for children, students, seniors, on special travel days and for return trips under certain conditions. The Arlanda Express is operated by A-Train, which also built the Arlanda Line as part of a public–private partnership. The company holds an exclusive concession to operate any train service between Stockholm and the airport. In addition, the company is free to charge other train operators that use the Arlanda Line and stop at Arlanda Central Station. Rolling stock The Arlanda Express is operated by seven four-car X3 electric