Chennai serves as a major gateway to southern India and the Chennai International Airport, comprising the Anna international terminal and the Kamaraj domestic terminal, is the third busiest airport in India. The city is connected to major hubs across Asia, Europe, and North America through more than 30 national and international carriers. The airport is the second busiest cargo terminus in the country. The existing airport is undergoing further modernisation and expansion, and a new greenfield airport is to be constructed at an estimated cost of 2,000 crore in Sriperumbudur.
The city is served by two major ports, Chennai Port, one of the largest artificial ports, and Ennore Port. The Chennai port is the largest in Bay of Bengal and India's second busiest container hub, handling automobiles, motorcycles and general industrial cargo. The Ennore Port handles cargo such as coal, ore and other bulk and rock mineral products. A smaller harbour at Royapuram is used by fishing boats and trawlers.
Chennai is the headquarters of the Southern Railway. The city has two main railway terminals. Chennai Central station, the city's largest, provides access to other major cities as well as many other smaller towns across India. Chennai Egmore is a terminus for trains to destinations primarily within Tamil Nadu; it also handles a few inter-state trains. The Chennai suburban railway network, one of the oldest in the country, consists of four broad gauge sectors terminating at two locations in the city, namely Chennai Central and Chennai Beach. Regular services are offered in the following sectors from these termini: Chennai Central/Chennai Beach - Arakkonam -Tiruttani, Chennai Central/Chennai Beach – Gummidipoondi - Sullurpeta and Chennai Beach – Tambaram - Chengalpattu - Tirumalpur(Kanchipuram). The fourth sector is an elevated Mass Rapid Transit System (MRTS) which links Chennai Beach to Velachery and is interlinked with the remaining rail network. Construction is underway for an underground and elevated Chennai Metro rail.
Chennai is well connected to other parts of India by road. Five major national highways link Chennai to Mumbai (via Bangalore),Kolkata, Kochi (via Coimbatore), Tiruchirapalli (Trichy) and Tirupati and onwards to the rest of the national highway system. Numerous state highways link the city to Puducherry and other towns and cities in Tamil Nadu and neighbouring states.The Chennai Mofussil Bus Terminus (CMBT), the terminus for all intercity buses from Chennai, is the largest bus station in Asia. Seven government-owned transport corporations operate inter-city and inter-state bus services. Many private inter-city and inter-state bus companies also operate services to and from Chennai. The Metropolitan Transport Corporation (MTC) runs an extensive city bus system consisting of 3280 buses on 643 routes, and moves an estimated 5.52 million passengers each day. Vans, popularly known as Maxi Cabs and 'share' auto rickshaws ply many routes in the city and provide an alternative to buses. Metered call taxis, tourist taxis and auto rickshaws are also available on hire. Chennai's transportation infrastructure provides coverage and connectivity, but growing use has caused traffic congestion and pollution. The government has tried to address these problems by constructing grade separators and flyovers at major intersections, starting with the Gemini flyover, built in 1973 over the most important arterial road, Anna Salai to the recently completed Kathipara Flyover.