The Central Government is responsible for development and maintenance of the National Highways system. The total length of the network, as of today, is 65,600 km. The Ministry is carrying out development and maintenance work of National Highways through three agencies viz. National Highway Authority of India (NHAI), State Public Works Departments (PWDs) and Border Road Organisation (BRO).

In order to give boost to the economic development of the country, the Government has embarked upon a massive National Highways Development Project (NHDP) being implemented by National Highways Authority of India (NHAI).

The Phase-I and Phase II of NHDP comprises

• Golden Quadrilateral, i.e., National Highways connecting four metropolitan cities, i.e., Delhi, Mumbai, Chennai and Kolkata having an aggregate length of 5846 Km.
  
  
• North-South and East-West Corridor which comprises 4-laning of 7300 Km of National Highways connecting North-South corridor from Srinagar to Kanyakumari with Cochin-Salem spur and East-West corridor from Silchar to Porbandar.
  
  
• 380 Km length of National Highways are proposed to be upgraded to 4-lane standards for providing connectivity to 10 major ports of the country to NHDP. (iv) Upgradation of 831 Km of other important National Highways. The total estimated cost of the NHDP Phase I & II having a total length of 14,357 km is about Rs. 64,639 crore.

NHDP Phase-III: NHDP Phase-III involves 4-laning of 12,109 km of NH having high-density corridor connecting State capitals, important tourist places, economically important areas etc. on PPP basis. The Government has approved implementation of 4,815 km under NHDP Phase-III A. The proposal for implementation of the balance length of about 7,294 km under NHDP Phase-IIIB has been approved recently.

NHDP Phase-IV: Phase IV of NHDP comprising 2-laning with paved shoulders of 20,000 kms of National Highway.

NHDP Phase-V: Phase V of NHDP comprising six laning of 6,500 km of existing 4 lane highways on Design Build Finance & Operate (DBFO) basis was approved on 5.10.2006. This includes 5,700 km of GQ and other selected stretches.

Consultancy works for a length of 1,225 km has already been awarded for feasibility study and bids for 180 km length are under evaluation. Civil works for a length of 148 km was awarded on BOT Concessions and for balance follow up actions are being taken to award the contracts on BOT basis.

NHDP Phase-VI: Government has recently approved the proposal for development of 1000 kms of access controlled four /six lane divided carriageway expressways under NHDP phase-VI on BOT basis at the cost of Rs. 16,680 crores (Rs.7,680 crore as contribution of Government/NHAI for utility shifting, land acquisition etc.).