National highways provide strategical connectivity to some of the major cities of India. Entire highway network of India is managed by the National Highway Authority of India-NHAI which is responsible for development and maintenance of highways.

On April 2010, the Ministry of Road Transport and Highways officially published a new numbering system for the national highway network. As per the new system, all north-south oriented highways will have even numbers increasing from the north to the south, also the east-west oriented highways will have odd numbers increasing from east to the west part of the country.

There are 266 national highways in India that cover a distance of about 76,818 Kms. The majority of the existing national highways are two-lane roads, many of which are now expanded to four-lanes, and some even to six or more lanes. Toll booths are built on most highways to serve the dual purpose of – collecting the road tax from the respective vehicle owners and to keep a security checkpoint.

Listed below are some of the distinguishing factors of some of India’s major National Highways:-

• National Highway 44 or NH-44, is the longest running highway (officially listed as running over 3,745 km). It starts from Srinagar and terminates in Kanyakumari covering the almost length of India from North to South.
• India’s shortest National Highway 966B covers a distance of 8 km between Kundannoor and Willingdon Island in Kochi, Kerala. It starts from Kundannoor near junction NH-544.
• There are 13 National Highways that stretch beyond the length of 1000 km.
• NH-44, also called North-South Corridor, passes through a maximum number of Indian states including Himachal Pradesh, Punjab, Haryana, Delhi, Uttar Pradesh, Madhya Pradesh, Maharashtra, Telangana, Andhra Pradesh, Karnataka, and Tamil Nadu.
• NH-1 is a National Highway in North India that connects the Kashmir valley to Leh and the rest of India. It runs through some extremely treacherous terrain and shut-offs because of avalanches or landslides during winters.
• NH-3 commonly referred to as the Agra–Bombay Highway or AB Road, is a major Indian National Highway. It originates in Agra,Uttar Pradesh and terminates in Mumbai,Maharastra.
• NH-4, also known as the Great Andaman Trunk Road, it connects Mayabandar, Port Blair and Chiriyatapu in Andaman & Nicobar Islands.
• NH-16 is a major National Highway in India, that runs along the east coast of Odisha, Andhra Pradesh and Tamil Nadu. Its northern terminal is at NH-19 near Kolkata and the southern terminal is at Chennai in Tamil Nadu. It is a part of the Golden Quadrilateral project undertaken by National Highways Authority of India (NHAI).
• NH-66 is one of the busiest National Highway in India that runs roughly north–south along the western coast of India, parallel to western ghats. It connects Panvel (south of Mumbai city) to Kanyakumari, passing through the states of Maharashtra, Goa, Karnataka, Kerala, Tamil Nadu.
• NH-27, an East-West National highway also called East-West Corridor, starts from Porbandar and terminates in Silchar. It passes through the states of Gujarat, Rajasthan, Madhya Pradesh, Uttar Pradesh, Bihar, West Bengal and Assam. It is the second longest National Highway in India after NH-44.
• NH-49 is a National Highway in southern India. It traverses coast-to-coast linking Cochin in Kerala with Dhanushkodi in Tamil Nadu. It crosses the famous Pamban Bridge before crossing into Rameswaram island with the maximum length of 440 km.
• The Golden Quadrilateral is the highway network connecting the four metros in India – i.e. Delhi, Mumbai, Chennai and Kolkata and several other cities. It connects several national highways throughout India. The completed Golden Quadrilateral passes through 13 states covering a distance of 5,846 km.