BEIJING, June 22 -- China's transition to electric vehicles has become one of the country's most celebrated industrial achievements.

But beneath the surge in sales lies a quieter problem: the rapid shift away from petrol-powered cars is weakening a key source of funding for the roads those vehicles travel on, according to South China Morning Post.

The challenge is emerging as local governments grapple with maintaining one of the world's largest road networks while facing mounting fiscal pressure.

New-energy vehicles, including battery-electric and plug-in hybrid models, accounted for more than 60 per cent of new car sales in China last month, data from the China Passenger Car Association showed.

The milestone reflects years of governm...