HANOI: Millions of exhaust-belching motorbikes zip through Hanoi’s narrow streets every day fueling its chronic air pollution, but authorities have backtracked from an ambitious plan to ban them in favor of electric two-wheelers. Vehicular emissions account for more than half of the capital’s pollution problem — some days it tops world rankings for hazardous air — but the city runs on two-wheelers, the vast majority of them powered by fossil fuels.

HANOI: Millions of exhaust-belching motorbikes zip through Hanoi’s narrow streets every day fueling its chronic air pollution, but authorities have backtracked from an ambitious…

HANOI, May 19 — Millions of exhaust-belching motorbikes zip through Hanoi’s narrow streets every day fuelling its chronic air pollution, but authorities have backtracked from...