India, July 30 -- Once called Mumbai's second lifeline after suburban trains, the Brihanmumbai Electricity Supply and Transport Undertaking's (BEST's) pulse has significantly dropped over the last few years.

And it is set to take a further hit, with as many as 180 buses running on CNG reaching the end of their lifespan in the next six to eight months, officials said. Meanwhile, new buses aren't being added to the fleet quickly enough.

BEST currently has around 2,670 buses in its fleet, of which it owns just 430. The rest are on wet leases-owned, operated, and maintained by private contractors appointed by BEST.

Of the 430 owned buses, 180 running on CNG are nearing their codal life of 15 years. The remaining six electric buses and 244 ...