The NHAI was created through the promulgation of the National Highways Authority of India Act, 1988. In February 1995, the Authority was formally made an autonomous body. It succeeded the erstwhile Ministry of Surface Transport.
It is responsible for the development, maintenance, management and operation of National Highways, totaling over in length.
Phase I: Approved in December 2000, at an estimated cost of INR 300 Billion, it included the Golden Quadrilateral (GQ), portions of the NS-EW Corridors, and connectivity of major ports to National Highways.
Phase II: Approved in December 2003, at an estimated cost of INR 343 Billion, it included the completion of the NS-EW corridors and another of highways.
Phase IIIA: This phase was approved in March 2005, at an estimated cost of INR 222 Billion, it includes an upgrade to 4-lanes of of National......