Economy of Tamil Nadu projects under operation in the public-private partnership (PPP) model. It is currently working on upgrading its road network, though the pace of work is considered slow. Tamil Nadu has a well-developed rail network as part of Southern Railway. Headquartered at Chennai, the present Southern Railway network extends over a large area of India's Southern Peninsula, covering the states of Tamil Nadu, Kerala, Puducherry, minor portions of Karnataka and Andhra Pradesh. Tamil Nadu has a total railway track length of 6,693 km and there are 690 railway stations in the state. The system connects it with most major cities in India.
History of Tamil Nadu in the Indian Union, Tamil Nadu was the seventh largest economy in 2005 among the states of India. The growing demands for skilled labour has caused increased number of educational institutions in Tamil Nadu. The widespread application of caste based affirmative action caused the state to have 69% of all educational and employment vacancies to be reserved to the backward castes. Such caste-based reservations have huge public support in Tamil Nadu, with no popular protests organised against its implementation. The politics of Tamil Nadu have gone through three distinct phases since independence. The domination of the Congress Party after 1947