The routes account for around 41 per cent of total railway traffic while covering just 16 per cent of the railway network, making capacity augmentation crucial as passenger and freight demand continues to rise across the country.

Union Railway Minister Ashwini Vaishnaw announced the expansion initiative, which includes the Delhi-Howrah, Howrah-Chennai, Chennai-Mumbai, Mumbai-Delhi, Delhi-Chennai, Mumbai-Howrah and Delhi-Guwahati corridors.

These routes connect some of India's most important cities and economic centres, serving as the backbone for both passenger travel and freight movement across the nation.

The proposed expansion aims to create four railway lines across these high-density corridors, enabling Indian Railways to handle substantially higher traffic volumes whilst improving operational efficiency.

Four-laning these critical corridors can help reduce congestion, improve train operations and create greater scope for running additional passenger and freight services.

The Delhi-Guwahati route holds particular significance for the Northeast, as it will strengthen the region's connectivity with the national railway network and support the movement of people and goods between the Northeast and other parts of the country.

Under Prime Minister Narendra Modi's vision, Indian Railways is moving towards four-laning the entire high-density network to increase capacity and support the growing movement of passengers and freight across the country.

The expansion is part of a broader infrastructure push by Indian Railways to modernise and increase capacity across its network.

The initiative responds to growing demand on routes that currently operate at saturated capacity, with the four-laning expected to significantly enhance the railway's ability to accommodate future traffic growth on these strategically important corridors.