Examples from other countries

Beijing

The Chinese city enforced a ban on cars on the basis of odd and even numbers during the 2008 Olympic Games. The curb, along with shutting down factories, helped cut the smog level by 20 per cent. Once the Games were over, authorities announced a one-day ban every week. But it also rapidly expanded its subway system, installing 228km to encourage usage of public transport.

London

In 2003, it implemented a £5 (Dh28) congestion charge for driving into the innermost streets of the city. With the result emissions were reduced by 12 per cent. The charge has now gone up to £10. Five years, later, a Low Emission Zone (LEZ) was introduced to regulate entry of trucks and buses into all of Greater London. It led to a drop of 20 per cent in tiny particulate matter.

Stockholm

The city implemented an LEZ in 1996. Vehicles are not allowed to enter the zone if they do not meet certain EU emissions norms. It brought emissions down by 20 per cent. The effect of this on the air quality was visible, with concentrations of certain pollutants down by 1.3 per cent and particulate matter down by 3 per cent.

Mexico City

Introduced the odd-even car numbers in 1989. The programme was initially successful in cutting air pollution, with carbon monoxide dropping by 11 per cent. But most people began buying a second vehicle (mostly used ones) to circumvent the ban. The long-term impact of the policy on carbon levels has risen by 13 per cent.

PTI ■ A traffic jam on the Ring Road in New Delhi. With 50 per cent of vehicles going off the road, there would be about 1.2 million fewer cars on the roads daily. The move is set to be rolled out from January 1, 2016.