The Delhi–Kolkata high-speed rail corridor is one of the route of the proposed high-speed rail in India. The line is part of the Diamond Quadrilateral Program, which seeks to unite the cities of New Delhi, Kolkata, Mumbai and Chennai via high speed rail. This travels along the Delhi–Howrah main line from Tundla to Howrah. The train expects to cut the journey time for the 1,500 km (930 mi) between the national capital of India, New Delhi, and the capital of the Indian state of West Bengal, the city of Kolkata, to just 5 hours 30 minutes.