National Highways of Pakistan (Urduقومی شاہراہ) consists of all public highways maintained by the National Highways Authority under the Ministry of Transport. It maintains over 12,000 kilometres (7,500 mi) of roadways organised into various classifications which crisscross the country and provide access to major population centers. National Highways are not to be confused with provincial highways, which are roads maintained by the respective provinces. Pakistan's national highways include the famous Grand Trunk Road, Indus Highway, Karakoram Highway and Makran Coastal Highway. All national highways in Pakistan are pre-fixed with the letter 'N' (for "national") followed by the unique numerical designation of the specific highway (with a hyphen in the middle), e.g. "N-5". Each numerical designation is separated by five numerals, i.e. N-5, N-10, N-15, etc. National Highways are distinct from 'Strategic Highways', which begin with the prefix 'S' and are controlled and operated by the Ministry of Defense.