as well. Traditionally, the easternmost border of Agder was Rygjarbit, which was thought to be Gjernestangen in the present-day municipality of Risør, but it could also be the strait between Askerøya and Lyngør in Tvedestrand. Transportation {{Historical populations |footnote = Source: Statistics Norway . |shading = off |1951|172753 |1960|185302 |1970|215874 |1980|225429 |1990|240906 |2000|257869 |2010|279024 }} Air The Arendal Airport, Gullknapp is a general aviation airport located outside of Arendal city. The airport was founded in 1984 with a long runway. Arendal Airport, Rådhuskaien is a former water airport in the cove of downtown Arendal, but it is now closed. Farsund Airport, Lista is a former public airport located with Lista. It opened in 1941 and closed in 1999. The airport was located at Lista. Mandal Airfield is a former military owned airport that is now closed. Kristiansand Airport, Kjevik is the only public airport in Southern Norway, in 2014 there were over 1 million travelers from the airport. Kjevik Airport has destinations to charter places, European cities and some of the largest Norwegian cities. The Airport opened in 1918 and is located at Tveit, from downtown Kristiansand, Kvadraturen. The IATA code is KRS and ICAO is ENCN. It is owned by Avinor. Kristiansand Airport, Kongsgårdbukta is a former water-airport located at Lund from 1934 to 1939. Kristiansand Naval Air Station is also a former water-airport located at Tangen from 1919 to 1949. Bus All bus lines and buses in Southern Norway are owned by Agder Kollektivtrafikk (AKT). Nettbuss serves the Kristiansand Region with local blue buses. In Kristiansand, the city buses are in service every day from 4:00 AM until 1:00 AM, extra night buses during the weekend and direct/extra buses during the rush hours. Setesdal Bilruter serves the Setesdal, Østre Agder, and Lillesand areas. Line 100 goes connects Arendal–Grimstad–Lillesand–Kristiansand. Bus lines from Setesdal go to both Arendal and Kristiansand. Line 150 goes from Arendal to Tvedestrand and Risør. Sørlandsruta'' serves the coastal towns and villages in Vest-Agder county. Line 200 is the main line going from Kristiansand to Mandal, Vigeland, Lyngdal, and Farsund. Some of the buses collaborate with the local buses from Lyngdal to Flekkefjord and Kvinesdal. Roads The European route E18 highway goes through Aust-Agder county to the east side of Kristiansand. The E18 goes near the shore and coastal towns and ends at Kristiansand. The European route E39 highway starts at the Kristiansand ferry port where