The first compressed natural gas (CNG) bus has taken to the roads of Kolkata in West Bengal. Currently, two CNG buses will run on a trial basis and if found operationally feasible, the conversion will be expanded. The two buses have been converted from diesel and will be operated by the West Bengal Transport Corporation (WBTC), which has nearly 1,000 buses in its fleet.

On June 21, 2021, the WBTC and the Bengal Gas Company Limited had signed a CNG bus fuel agreement. The foundation for the first CNG station in Kolkata for government buses was laid and it is expected to become operational by December 2021.