information:extraction, quality:correction, structural:reformatting
Rail

The rail network in Tamil Nadu forms a part of Southern Railway of Indian Railways, which is headquartered in Chennai with four divisions in the state namely Chennai, Tiruchirappalli, Madurai and Salem. As of 2023, the state had a total railway track length of 5,601 km (3,480 mi) covering a route length of 3,858 km (2,397 mi). There are 532 railway stations in the state with Chennai Central, Chennai Egmore, Coimbatore Junction and Madurai Junction being the top revenue earning stations. Indian railways also has a coach manufacturing unit at Chennai, electric locomotive sheds at Arakkonam, Erode and Royapuram, diesel locomotive sheds at Erode, Tiruchirappalli and Tondiarpet, Steam locomotive shed at Coonoor along with various maintenance depots.

Chennai has a well-established suburban railway network operated by Southern railway, covering 212 km (132 mi) which was established in 1928. The Mass Rapid Transit System (MRTS) is an elevated urban mass transit system established in 1995 operating on a single line from Chennai Beach to Velachery. Chennai Metro is a rapid transit rail system in Chennai which was opened in 2015 and consists of two operational lines operating across 54.1 km (33.6 mi) in 2023. Nilgiri Mountain Railway is a 1,000 mm (3 ft 3 + 3 ⁄ 8 in) metre gauge railway in Nilgiris district which was built by the British in 1908 and is the only rack railway in India.