Road network in Tamil Nadu

[4][5] Road stretches that have heavy traffic intensity of more than 30,000 passenger car units (PCUs) connecting different state capitals, major ports, large industrial areas and tourist centers are designated National Highway by the Indian government.

The wing has eight circles namely Chennai, Coimbatore, Madurai, Salem, Tiruchirappalli, Tirunelveli, Tiruppur, and Villupuram.

Similar to SH and MDRs, Construction and Maintenance wing of Highways Department executes ODR related works.

ECR Road runs from Kudumiyandithoppu till outskirts of Pondicherry for a total length of 113 km (70 mi).

Recently Tamil Nadu Government has upgraded the ECR road till Mahabalipuram to four lanes at a cost of ₹672 crore (US$78 million).

[16] In 2010, an announcement was made in the State Budget to build a Western Ring Road at a cost of ₹ 2.84 billion for 26 km.

[18] The Ennore–Manali Road Improvement Project (EMRIP) was developed by a special purpose vehicle formed by National Highways Authority of India (NHAI), Chennai Port Trust (CPT), Ennore Port Limited (EPL) and Tamil Nadu Government (GoTN) at a cost of Rs 600 crore.

The ₹1,655 crore (US$190 million) Elevated Expressway project was awarded to Hyderabad based Soma Enterprises.

The 62-km long Outer Ring Road with six lanes from Vandalur to Minjur via Nemellichery was awarded to GMR consortium by Chennai Metropolitan Development Authority to implement the project on a Design, Build, Finance, Operate and Transfer (DBFOT) basis.