Indian Railways has launched an extensive programme to convert the metre and narrow gauges to broad gauges. Moreover, steam engines have been replaced by diesel and electric engines. This step has increased the speed, as well as, the haulage capacity. The replacement of steam engines run by coal has also improved the environment of the stations. Metro rail has revolutionalised the urban transport system in India. The replacement of diesel buses with CNG-run vehicles along with the introduction of the metro is a welcome step towards controlling air pollution in urban centres.

What puts a lot of pressure on the centralised railway management system of India?

It's very large size.

Indian Railways is the largest government undertaking in the country. The length of the Indian Railways network was 67,956 km (Railway yearbook 2019-20). It's very large size puts a lot of pressure on a centralised railway management system. Thus, in India, the railway system has been divided into 16 zones.