The UK has a railway network of  in Great Britain and  in Northern Ireland. Railways in Northern Ireland are operated by NI Railways, a subsidiary of state-owned Translink. In Great Britain, the British Rail network was privatised between 1994 and 1997, which was followed by a rapid rise in passenger numbers. The UK was ranked eighth among national European rail systems in the 2017 European Railway Performance Index assessing intensity of use, quality of service and safety. Network Rail owns and manages most of the fixed assets (tracks, signals etc.). HS2, a new high-speed railway line, is estimated to cost £56 billion. Crossrail, under construction in London, is Europe's largest construction project with a £15 billion projected cost.