I landed in Delhi at the tail-end of an experiment to limit the number of vehicles on the road. Here’s a piece in Nature about how researchers leapt on the opportunity to study the effects. 

New Delhi may be the world’s most polluted city, but it’s making an effort to relinquish that title. With pollution from particulate matter at potentially lethal levels early last December, city officials took a drastic step: they announced that they would temporarily restrict the use of private vehicles by allowing owners to drive only on alternate days, based on the sequence of their number plates.

The initial results of that 15-day trial, which began on 1 January, are now in.

Read the whole piece here.