An excellent network of roadways very well connects the entire state of Tamil Nadu. The total length of network of roadways in Tamil Nadu is about 1.70 lakh kms. Both private and Government buses run on the roads of Tamil Nadu. The private bus operators connect the important Indian cities with Tamil Nadu and the government buses run in the states of Southern India. State Express Transport Corporation run inter state buses and connects Chennai with the states of Karnataka, Kerala, and Andhra Pradesh.
The assets and liabilities of Tamil Nadu State Transport Department in Tirunelveli and Kanniyakumari Districts and the Pandiyan Roadways Corporation Limited was taken over by Kattabomman Transport Corporation Limited and it initiated its business from 01.01.74. The headquarters of the Kattabomman Transport Corporation Limited was located at Nagercoil and it connected Tirunelveli and Kanniyakumari Districts to the other parts of the state.
The distance between Chennai and some of the important Indian cities are as follows:
Kancheepuram: 75 Kms
Bangalore: 334 Kms
Pondicherry: 162 Kms
Tirupati: 154 Kms
Mamallapuram: 58 Kms
Vellore: 145 Kms
The Highways Department (HD) of Tamil Nadu looks after the maintenance and construction of roads which comprises of the National Highways, State Highways and Major District Roads in Tamil Nadu. The Department has 7 wings spread in the 30 districts of Tamil Nadu with nearly 120 Divisions and sub offices in about 450 places. The total length of National Highways is 4254 km, State Highways is 6849 km, major District Roads measure 7569 km and Other District Roads are 41002 km in length.
The State Highways are arterial routes of a State, linking district headquarters and important towns within the State and connecting them with National Highways or Highways of the neighboring States. The187 State Highways in Tamil Nadu connect the different district headquarters and important towns of Tamil Nadu and link them with National Highways or Highways of the bordering States. The entire State Highways in Tamil Nadu measures 6849 km, out of which 279 km is multilane highways, 4005 km is double lane highways, 1180 km is intermediate lane and 1385 km is single lane.


