The Indian capital of Delhi has long suffered some of the most intractable air pollution in Asia. Ever-growing car and motorcycle use has been the principal culprit.
A 2014 survey by the World Health Organization ranked the city’s air quality as the world’s worst. Air pollution is estimated to kill over 600,000 persons each year in India. The economic impacts from congestion and lost productivity are likewise staggering.
Help may be on the way.
Officials experimented last month with an odd-even license plate scheme that intended to remove half of the motorized vehicle fleet from the roads each day. Odd and even plate numbers alternated the days on which cars could be used.
The program did include a long list of exemptions that could have nullified any vehicle reductions: women were exempted so they could avoid possible violence and harassment on public transport, Likewise, additional exemptions were granted to senior government officials, motorcycles, disabled drivers, emergency services, and vehicles using natural gas.
Despite these exemptions the Delhi experiment did appear to reduce congestion at certain times. Unfortunately however, due to lingering exhaust fumes and pollution from other sources, the air quality did not markedly improve during the test period, which concluded on 15 January. With the conclusion of the 15-day trial scheme, officials will now assess whether or not to take the program forward.
Historically, license plate restrictions have been employed in various cities of Latin America with varying results in Mexico City, Bogota, Quito, Santiago, and Sao Paulo, as well as in Paris, Manila, and Beijing. The simpler even-odd numbering schemes have tended to merely encourage households to purchase second cars with a different number plate to bypass the restrictions, and most of those second cars tend to be older, used vehicles that ultimately make air quality even worse.
In Bogota, though, a smarter structure has been employed, with four plate numbers restricted on a daily basis. These numbers are then rotated on an annual basis to discourage second car purchases. Other effective measures include ensuring households are given the same ending number on plates for any additional vehicle purchases. Strict vehicle emissions testing and fuel standards likewise help.
License plate restrictions are part of a larger set of tools known as transportation demand management, which attempts to discourage private vehicle use in favor of public transport and non-polluting modes. Other tools include congestion charging, like those implemented in cities such as Singapore, London, Stockholm, and Oslo, as well as car ownership rationing and parking restrictions. Parking levies are particularly effective, as they charge a daily fee to the owner of each non-residential parking space, regardless of whether the parking space is used. As such, parking levies not only discourage car use but also raise funding which can be used for more sustainable options such as public transport and pedestrian facilities.
The core issue, though, for Delhi and other growing cities in developing Asia is the insatiable demand for car ownership. Each day approximately 1,400 new cars are registered in the Indian capital, meaning a new lane of peak hour traffic is added about each 1.5 days. No amount of road building could ever keep up with such numbers.
In 2004, the Supreme Court of India mandated the use of natural gas in public transport and auto-rickshaws in Delhi. For a time, this move produced cleaner air. However, these health gains were eventually wiped out with the ever-growing motor vehicle fleet. Without more fundamental changes, the same result may well happen to any odd-even scheme.
The Delhi license plate scheme has been a bold experiment, and city officials deserve much credit for making it happen. If they were to make the scheme permanent, including features to discourage second-car purchases would certainly be advisable. More fundamentally, though, reapportioning road space and investment toward public transport, pedestrians, and cyclists would be the pivotal game-changer.
Delhi’s force to counter car dominance is indeed awakening. Will the Jedi of sustainable transport find a way to counter the dark side of rampant motorization? We will have to wait until the next episode, but the recent experiment may give new hope to the world’s most polluted metropolis.