The correct answer is Golden Quadrilateral. Explanation & Key Takeaways: • The Golden Quadrilateral is a network of highways in India connecting the four major metropolitan cities: New Delhi, Mumbai, Chennai, and Kolkata. • It is one of the largest highway projects in India and was initiated by the Government of India under the National Highways Development Project (NHDP). • The project was launched in 2001 and was completed in phases, aiming to improve connectivity between major cities and promote economic development. • The Golden Quadrilateral spans a length of approximately 5,846 kilometers, covering major industrial and agricultural centers of India. • This expressway facilitates rapid transportation of goods and passengers, significantly reducing travel time and fuel consumption. Related Concepts: • Features of the Golden Quadrilateral: • The expressway is designed to meet international standards of road infrastructure. • It connects cities with high economic and industrial significance, boosting trade and commerce across the nation. • The road infrastructure includes multiple lanes, bypasses, flyovers, and service roads to ensure smooth traffic flow and reduce congestion. • Importance: • The Golden Quadrilateral plays a vital role in reducing travel time and improving connectivity between India's major cities. • It facilitates economic growth by enabling faster transportation of goods and services. • Improved road infrastructure has led to a rise in tourism, industrial development, and urbanization. • Other Related Projects: • The North-South and East-West Corridor connects Srinagar to Kanyakumari and Silchar to Porbandar, respectively. • National Highway 44 is India's longest highway, connecting Srinagar to Kanyakumari, but it is not part of the Golden Quadrilateral. • The East-West Corridor is another major infrastructure project aimed at improving connectivity across India. • Facts and Figures: • The Golden Quadrilateral was built at a cost of approximately Rs. 60,000 crore. • It includes four-lane and six-lane roads with advanced features like electronic toll collection systems. • The project is maintained by the National Highways Authority of India (NHAI).