December 1, 2025: Indian Railways’ seven High Density Network (HDN) corridors, which handle 41 percent of the country’s rail traffic despite constituting just 16 percent of the network, are operating far beyond capacity in many sections. To address this, the Centre has approved construction of a third and fourth line on the 32-km Badlapur-Karjat section in Maharashtra, a critical extension of the Mumbai Suburban Corridor and a key link on the 1,238-km Mumbai-Chennai HDN.
The HDN comprises passenger-freight corridors where trains frequently exceed optimal capacity, causing congestion and delays. Out of 11,051 km of HDN, only 4.6% operate below 80 percent of capacity. Nearly 29.5% of routes see 120-150% utilisation, and 14.1% run at over 150%. For instance, the 28-km Karjat-Lonavala section of the Mumbai-Chennai corridor sees 67 trains each way daily against a capacity of 40, reaching 167% utilisation.
The seven HDN corridors span the country: Howrah–Delhi, Howrah–Mumbai, Mumbai–Delhi, Delhi–Guwahati, Delhi–Chennai, Howrah–Chennai, and Mumbai–Chennai. Most sections in these corridors operate above 100% capacity, with HDN 4 (Delhi–Guwahati) having 96% of its route over 80% utilisation. By 2031, projections indicate 50% of HDN will operate at over 150% capacity, highlighting the urgent need for expansion.
Decongestion efforts include line-doubling, tripling, quadrupling, and in some sections, penta/hexa-lining. From 2021-25, Indian Railways completed over 10,000 km of such projects. Dedicated Freight Corridors, with Eastern DFC fully operational and Western DFC at 96.4%, are expected to divert freight, easing passenger traffic on HDN.
Currently, HDN consists of 250 km single line, 8,113 km double line, 2,040 km triple line, 625 km quadruple line, and 23 km penta/hexa line. The National Rail Plan recommends upgrading HDN 1 and HDN 4 to triple lines and HDN 2, 3, 6, and 7 to triple or quadruple lines to meet future passenger and freight demand, ensuring India’s busiest corridors remain the backbone of the rail network.
Source: The Indian Express
