Curbs on cars: A tale of two polluted cities

The findings of the Beijing-inspired Jan 1-15 trial car ban in polluted New Delhi and surrounding areas are not yet out.

When they become available, smog-hit Beijing might like to review them. Beijing and New Delhi, besides being national capitals, are comparable in terms of population (22 million and 16 million) and the number of motor vehicles (9 million and 7.5 million).

One-third of Delhi's 3 million cars were off the roads during the trial. Cars with license plates ending in an even number were allowed on even dates, and cars with odd-number plates on odd dates. Vehicles of the emergency services, security and police forces, VIPs, single women and cab services were exempted.

Media reports suggested that, during the trial, hazardous PM2.5 particulates hovered between "very poor" and "severe", well above the World Health Organization-prescribed safe limit. But Delhi claimed pollution eased and the roads were decongested.