Getting Odd-Even Right - Lessons from Beijing, Paris, and London

We know by now that air pollution is not a standalone problem in a city but is essentially a symptom of inadequate planning. Policymakers can implement one-off solutions against air pollution but the best short-term results are possible only when they are fully implemented with no exemptions. One example is Beijing during the 2008 Olympics. Based on satellite observations, and during the two months when stringent restrictions were in place, the levels of nitrogen dioxide resulting from fossil fuel combustion plunged nearly 50% and the levels of carbon monoxide fell by almost 20%. The measures were good at quickly lowering the pollution but since they weren’t addressing the root problem, they could do nothing once the stay order was lifted. The battle against air pollution in Beijing recently led to an announcement of ‘anti-smog police force‘ and an expenditure of $2.6 billion to bring back clear sky days to the city.

The measures introduced in Beijing have become somewhat of landmark examples to achieve quick mitigations. These include a 50% cap on vehicles everyday based on the registrations, full support from the public transport sector, shutdown of industries and power plants within a radius of 100 km for at least a month before the games began and a strict enforcement of a ban on burning coal and biomass for cooking and heating. It was a matter of national pride; every citizen in the city chipped in to make sure the sky was blue and the air was clear.

The most talked about scenario is the 50% cap – a.k.a. the odd-even program. Key features that led to the program’s success were limiting the exemptions to emergency vehicles, thousands of number plate recognition cameras to aide traffic police and a wide network of railways and roads to take on the additional load. This was a proactive measure, knowing that air quality during the games would be bad but had to be better.

In 2016, the Delhi government played with the odd-even theme twice, for two weeks each in January and April, with a lot of exemptions and even a temporary increase in public transport capacity. Neither pilot pointed to a clear reduction in pollution. The reasons are plenty: the share of pollution from other sources is equally significant; the prevalent weather brought down pollution from the fires in Uttarakhand and there is limited information to statistically argue for success. General reports showed lesser congestion, faster speeds on the road and 13% more daily revenue for the Delhi Transport Corporation.

In December, 2016, Paris also implemented an odd-even program, in advance, due to an anticipated red alert for the city, and to make the program a success, made all public transport modes free. Their biggest advantage is that transport is their only big source of pollution in the city, followed by coal and wood burning for heating purposes, which means cutting down the traffic by 50% and a wide media campaign to alert people to not burn coal or wood, but use electricity for heating, gives them immediate benefits.

Read more on this @ the WIRE