The Chennai Metro is a rapid transit system serving the city of Chennai, Tamil Nadu, India. It is the third longest metro system in India after Delhi Metro and Hyderabad metro. The system commenced service in 2015 after partially opening the first phase of the project. The network consists of two colour-coded lines covering a length of . The Chennai Metro Rail Limited (CMRL), a joint venture between Government of India and the Government of Tamil Nadu built and operates the Chennai Metro. The system has a mix of underground and elevated stations and uses standard gauge. The services operate daily between 4:30 and 23:00 with a varying frequency of 5 to 14 minutes. As of November 2019, about 121,000 people use the service on a daily basis. There are 52 trains with four coaches each, making a total of 208 coaches, operating in the first phase and its extension.