High Quality Content by WIKIPEDIA articles! The Follo Line (Norwegian: Follobanen) is a planned 22.5-kilometer (14.0 mi) high-speed railway between Oslo and Ski, Norway. Running parallel to the Østfold Line, it will be engineered for 250 km/h (155 mph). Terminal stations will be Oslo Central Station and Ski Station. Most of the line, 19 kilometres (12 mi), will be in a single tunnel, which will be the longest railway tunnel in the country. Construction is estimated to start in 2013, and may be completed by 2018. The Follo Line will increase capacity from twelve to forty trains per hour along the South Corridor, and will allow express and regional trains to decrease travel time from Ski to Oslo from 22 to 11 minutes. The line is prospected to cost 11 billion Norwegian krone (NOK).