The railway system in Great Britain is the oldest in the world, with the world's first locomotive-hauled public railway opening in 1825. As of 2006, it consists of of standard gauge lines (the 16th largest in the world), of which are electrified. These lines are single, double or quadruple track. In addition, a number of narrow gauge lines operate in parts of the country. The British railway network is connected with that of continental Europe by an undersea rail link, the Channel Tunnel, which opened in 1994. Despite its track length, it is one of the busiest railways in Europe with 20% more train services than France, 60% more than Italy and more than Spain, Switzerland, The Netherlands, Portugal and Norway combined.