Chennai is one of the cities in India that is connected by the Golden Quadrilateralsystem of National Highways.It is connected to other Indian cities by four major National Highways (NH) that originate in the city. They are NH 4 to Mumbai(via Bengaluru, Pune), NH 5 to Kolkata (via Visakhapatnam,Bhubaneswar), NH 45 to Theni (via Villupuram, Tiruchirapalli, Dindigul) andNH 205 to Madanapalle (via Tirupati). Chennai is connected to other parts of the state and the Union Territory of Puducherry by state highways.
The government has constructed grade separators and flyovers at major intersections, and built Inner Ring Road and Outer Ring Road.The Gemini flyover, built in 1973 crosses over the arterial road, and eases the traffic movements towards Anna Salai and towards the Kathipara Flyover. As of 2011, according to the Transport Department, there were 25.8 lakh two–wheelers and 5.6 lakh four–wheelers in the city, and the Metropolitan Transport Corporation (MTC) bus fleet were 3,421, which was 0.1% of the total vehicular population of the city.
When opened, the Chennai Mofussil Bus Terminus (CMBT) was the largest bus station in Asia. It is the main intercity bus station of Chennai,administered by7 government-owned transport corporations, which operate intercity and interstate bus services. There are many private bus companies that provide similar transport services. The MTC provides an exclusive intracity bus service, consisting of 3,421 buses on 724 routes, which provides transportation to 55.2 lakh passengers daily. The Tamil Nadu State Transport Corporation operates Volvo air-conditioned services from Chennai to nearby cities like Pondicherry, Vellore, Hosurand Trichy.
The other means of road transport in the city include vans, regionally known as Maxi Cabs, auto rickshaws, on-call metered taxis and tourist taxis.
Chennai outer ring road is 62.3 km long connecting NH 45 (GST Road) at Perungalathur, NH 4 (GWT Road) at Nazarathpet, NH 205 (CTH Road) at Nemilicherry(Thiruninravur), NH 5 (GNT Road) at Nallur and TPP road at Minjur under the process by Chennai Metropolitan Area.