Indian National Highways are essentially long-distance roadways that are maintained by the Central Government. Though they make up about 2 percent of the road network, they carry almost forty percent of the total national traffic. The strength of the Indian National Highways is almost 70,548 Kms and they serve to connect all the major cities and capitals. Mot of the highways is two-laned with paved roads. They might be broader in developed areas with up to four lanes, and near large cities they can go up to eight lanes. The roads are well-maintained in the developed states and are free of potholes. It must be stated here that very few of India`s National Highways are made of concrete. It has been estimated that as of 2010, 19,064 km (11,846 mi) of the National Highway system still consists of single-laned roads. The government is currently working to ensure that by December 2014 the entire NH network consists of roads with two or more lanes.

Historical Development of the Indian National Highways
In ancient times the ruling monarchs had established brick-laden roads in their cities. In the 19th century, the British upgraded the highway network along with building roads in treacherous terrains such as the Western Ghats. The most famous highway of medieval India was the Grand Trunk Road. The Grand Trunk Road begins in Sonargaon near Dhaka, Bangladesh and ends in Peshawar, Pakistan. It travels through important Indian cities and route such as Patna, Varanasi, Kanpur, Agra, Delhi, Panipat, Pipli, Ambala, Rajpura, Ludhiana, Jalandhar and Amritsar.

National Highways Authority of India
The National Highways Authority of India Act, 1988 led to the constitution of the National Highways Authority of India (NHAI). It is responsible for the development, maintenance and management of the National Highways entrusted to it and for matters connected or incidental thereto. The Authority was operationalised in Feb, 1995. It succeeds the previous Ministry of Surface Transport.

National Highways Authority of India is mandated to implement National Highways Development Project (NHDP) which is India`s Largest ever highways project. It seeks to provide world class roads with uninterrupted traffic flow. The NHAI has been mandated to implement the Rs. 54,000 Crores (US$ 13.2 billions) National Highway Development Project (NHDP), which includes the Golden Quadrilateral (GQ) and the NS-EW Corridor (NSEW) corridors.

National Highways in India
The longest National Highway in India is the NH7 which runs from Varanasi in Uttar Pradesh to Kanyakumari at the southern most point of the Indian mainland, in Tamil Nadu covering a distance of 2369 km, and passing through the metros like Jabalpur, Nagpur, Hyderabad and Bengaluru. The shortest National Highway is the NH47A. It covers a total distance of 4.168 Kms and runs the stretch from the Ernakulam-Kochi port. It must be mentioned here that India has the distinction of having the world`s highest drivable highway connecting Manali to Leh in Ladakh, Kashmir. Some of the other important National Highways are the NH4 from Pune to Bengaluru, NH2 running from the Uttar Pradesh border to the Jharkhand border, NH21 from Punjab to Haryana, NH1 and 2 in Delhi, NH 17 in Goa and many more.

Highways form a very important part of the economic backbone of the country. They often help to facilitate some major developments along their routes. Moreover, many new towns have sprung up along the major highways. Highways also have large numbers of small restaurants and inns (known as dhabas) along their length. They serve popular local cuisine and serve as truck stops. They are of immense significance today due to the diminishing borders of a global world and they help facilitate trade, commerce and tourism. The Government of India has launched major initiatives to upgrade and strengthen National Highways through various phases of National Highways Development project (NHDP). The National Highways Development Project, currently being implemented, seeks to massively expand India`s highway network. Some of the Busy National Highway sectors in India have been converted to 6 or 4 lane expressways for example, Delhi-Agra, Delhi-Jaipur, Ahmedabad-Vadodara, Mumbai-Pune, Mumbai-Surat, Bangalore-Mysore, Bengaluru-Chennai and Chennai-Tada. Phase V of the National Highway Development Project is looking to convert all 6000 kms of the Golden Quadrilateral Highways to 6-lane highways/expressways by 2012.