With the Delhi government introducing the next odd-even vehicle rationing scheme from April 15, it becomes crucial to address certain concerns. Is it largely a move to improve Delhi’s air quality or is it targeted to decongest city roads? Have countries elsewhere adopted such a scheme successfully? If yes, does an immediate success also guarantee success over time? What lessons can be learnt?
According to a WHO global survey of 1,600 cities, Delhi is the most polluted city in the world, with pollution levels 20 times higher than acceptable. Clean air has become scarce and is probably the major reason for the government to intervene. But, if this is so, then the policy-makers have failed to target effectively.
In Delhi, the estimated emission load from all sources of particulate matter (PM) is 147.2 thousand kg per day. It is largely from road dust (52%), followed by emissions from domestic household and construction activities (19%). Diesel generators too contribute substantially. In fact, vehicular emissions constitute only 7% of the total. Thus, targeting only the vehicular category may not necessarily be the best policy for containing air pollution. However, it remains important to acknowledge that vehicular pollution is the most harmful, as it penetrates the lungs deeply. Also, auto-exhaust emissions are a concern as roadside vegetation and soil are immediate receptors of auto-exhaust lead. This is on account of the PM that is emitted due to adding ‘lead’ to petrol to improve its antiknock property.
As per a 2015 Planning Commission report, there are 8.8 million vehicles in Delhi, of which 64.36% are motorcycles and scooters, while 31.6% are cars and jeeps. With respect to vehicular pollution, trucks pollute the most, followed by two-wheelers, and then cars. The irony of odd-even is that cars contribute to just 10% of all PM10 and PM2.5 emissions by vehicles, while a major chunk of over 30% is by two-wheelers. Thus, targeting only cars is questionable.
But if the objective is to decongest Delhi roads, then policy-makers need to state this explicitly. In this context, there are several lessons. Road space rationing is not new. Its roots lie as early as 45 BC, when Julius Caesar, noticing congestion problems associated with carriages and carts pulled by horses in many Roman cities, declared the Centre of Rome off-limits from 6 am till 4 pm. Later, such a policy was adopted by other countries. Bans have been observed in Athens (1982), Santiago (1986, 2001), Mexico and Bogota (1989), Metro Manila (1995), Sao Paulo (1997), La Paz (2003), San Jose (2005), Beijing (2008, 2010), Quito (2010) and Paris (1997, 2014). Places where road space rationing was based on odd-even ply are Rome, Paris, Bogota, Beijing, Mexico, Manila and Delhi. In Bogota, Manila and Sao Paulo, it has also been a mix of peak hour movement of vehicular traffic and alternate number ply. Evidence on policy implementation remains mixed, as both success and failures coexist. Places where odd-even succeeded in reducing congestion and improving air quality are Paris, Mexico (initially in 1989) and Beijing (in 2008). The success factors have largely been due to (1) small size of cities with low population density; (2) better access to public transportation; (3) test check at places for sample response (like in Beijing and Paris) before full implementation; (4) incentives in the form of rebate in vehicle taxing for a quarter, to compensate private vehicle owners for the inconvenience caused, as in Beijing.
Cities where vehicle space rationing failed to specifically improve air quality are Bogota (1989), Mexico (1989) and Beijing (2010). There were various factors that contributed to its failure.
w Incorrect targeting of cars instead of two-wheelers and commercial vehicles that caused higher pollution;
w Adequate time or pre-warning before implementation (in Mexico, it led to an increase in the number of private vehicles on road over time as households adjusted to the scheme and purchased more cars to beat the odds of odd-even);
w Shift from peak-hour to off-peak hour driving; in Bogota, the scheme was implemented during peak hours only;
w Not addressing deficiencies in the city’s planning and design framework on which public transport system rests, before implementing such a policy.
Therefore, it is important to understand the objective behind Delhi government’s policy initiative. If it is to mitigate air pollution, then the policy remains flawed. First, it ignores a significant contribution to pollution by sectors other than transport. Second, even within the vehicular category, focusing only on diesel and petrol cars is questionable. However, in case the objective is to decongest Delhi’s roads, then surely this policy is expected to be successful, at least in the immediate period. But the effectiveness of the policy will be short lived, as over time the richer Delhiites shall end up buying more alternate numbered cars or more ecofriendly cars, get CNG kits installed in existing cars, or simply switch cars among friends and family. After all, economists do know that demand elasticities tend to be higher over time. The successful decongestion of Delhi’s roads during the first phase of this policy (January 1-15) was primarily because of low elasticity in the immediate period, which with time may not happen. This observation is supported empirically in Beijing’s case, as road rationing implementation to improve air quality was successful initially in 2008, but not as successful when tried again in 2010.
Traffic congestion is a non-linear function of traffic volume, meaning that when a road network is at capacity, adding or subtracting even a single vehicle has disproportionate effects for the network. For instance, a 5% reduction in traffic volumes on a congested highway (say, from 2,000 to 1,900 vehicles per hour) is expected to cause a 10-30% increase in average vehicle speeds. A 2009 study by the INRIX Corp reveals that US traffic congestion decreased nearly 30% from 2007 to 2008 due to a 4% reduction in total traffic volumes. Surprisingly, even if total volume changes are modest, demand management can have a sizeable impact on congestion. This teaches us several lessons. For instance, allowing flextime (and telework) can assist commuters in matching transit and rideshare schedules, as does allowing time shifts from peak to off-peak hours. Congestion pricing, parking pricing and distance-based charges can also reduce traffic congestion. High-occupant vehicles (rideshare vehicles)—an important component of many regional transportation demand management (TDM) programmes—must be given priority. Having lower speeds and no intersections, and one-way streets and reversible lanes, can also prove effective during peak hours. Since a significant portion of traffic congestion arises due to some sort of a traffic incident, such as a disabled vehicle, a crash or dangerous driving, in such cases ‘incident detection and management’ should remain top priority. Measures to improve last-mile connectivity with metros and buses have to be strengthened for meeting Delhi’s transport challenge. An urgent need for commuter-friendly walkways and cycle paths can hardly be challenged. What remains crucial is for the government to educate the public towards social responsibility, and supplement it by improving the existing infrastructure of public transport. Raising awareness on the negative externalities caused by vehicle drivers is also important. The larger goal of social responsibility is to encourage commuters towards adopting favourable actions that ensure sustainability for all.
Future endeavours must include measures imposing curbs on construction activities, and curbing the use of diesel generators at homes and offices. Needless to say, with roads decongested and cleaner air, Delhiites are expected to move away from the confrontational road-rage attitude.
While we cannot change the past, we need to change our attitude towards the present problems, to have a promising future. The future that we seek needs a foundation of maturity, justice and prioritising society over self. Before the access to quality air is acknowledged as a human right, we need to address the challenge. Citizens and governments have to put forward their best efforts to confront the problem. Small steps have been taken; there are miles to go.
Simrit Kaur is professor of Public Policy; Megha Jain is research scholar, Faculty of Management Studies, University of Delhi