The railway official said that primarily the elevated tracks may be planned for the Diamond Quadrilateral Corridor covering Delhi-Mumbai-Chennai-Kolkata-Delhi as these cities have to be put on the high-speed rail corridor. Six corridors have been identified for technical studies on setting up of high-speed elevated rail corridors Delhi-Chandigarh-Amritsar, Pune-Mumbai-Ahmedabad, Hyderabad-Kazipet-Dornakal-Vijayawada-Chennai, Howrah-Haldia,Chennai-Bangalore-Coimbatore-Kochi-Thiruvan-anthapuram, Delhi-Agra-lucknow-Varanasi-Patna.