MTR is regarded as one of the world's leading railway operators. It was established in 1975 with a mission to construct and operate, under prudent commercial principles, an urban metro system to help meet Hong Kong's public transport requirements. Its rail network stretches 218 kilometres in total, including nine urban lines, the Airport Express and a light rail system in the New Territories. The network carries over 4 million passengers every weekday; its total patronage for 2011 was 1.6 billion.