What four major Indian cities are connected by the Golden Quadrilateral Super Highway?

The Golden Quadrilateral (GQ) is a national highway network connecting most of the major industrial, agricultural and cultural centres of India. It forms a quadrilateral connecting the four major metro cities of India, namely - Delhi (north), Kolkata (east), Mumbai (west) and Chennai (south). Other cities connected by this network include Ahmedabad, Bengaluru, Bhubaneswar, Jaipur, Pune, Surat, Ajmer, Varanasi, Allahabad, Agra, Mathura, Gandhinagar, Udaipur, Vadodara and many more. The main objective of this super highway is to reduce the distance and time between the four mega cities of India.

At 5,846 kilometres (3,633 mi), it is the largest highway project in India and the fifth longest in the world. It is the first phase of the National Highways Development Project (NHDP), and consists of four- and six-lane express highways, built at a cost of 600 billion Rupees (US$8.4 billion). The project was planned in 1999, launched in 2001, and was completed in 2012. The Golden Quadrilateral project is managed by the National Highways Authority of India (NHAI).