TEE 24 0 6 1 ESMAPC AA THE WORLD BANK VehicularAir Pollution: Setting Priorities A ir pollution is viewed as a serious problem in many actually small compared to other sources-such as refuse cities in South Asia. Many city governments hold burning, emissions from informal sector cottage industries, transport largely responsible and have adopted, or large industrial emission sources-then aggressively targeting are considering, technological measures to reduce vehicle vehicle exhaust may not improve air quality much. In this emission. This note outlines a framework for the appraisal case, the primary focus should be to consider what and selection of appropriate measures in the sector. environmental benefits can be achieved through marginal adjustments to transport policy rather than comprehensive A Framework for Policy Appraisal and costly solutions. The first step is to answer a sequence of questions to identify A common error is to conclude that transport is the major what needs to be targeted. polluter on the basis of estimates of total pollutants emitted in tons per year. Such calculations reflect the fact that, in terms * Is outdoor air pollution important? of weight, carbon monoxide, mostly from gasoline vehicles, * If so, what are the most serious pollutants? dominates in nearly all cities, but ignores the varying toxicity * Does transport contribute significantly? . of different pollutants. From a health impact perspective, examining contributions of different emission sources to fine * What transport activities do most damage? particulate matter (PM) would be more appropriate in South Asia. Emissions inventories typically show that transport is Is air pollution important? an important but a minority contributor to PM pollution. The impact of outdoor air pollution on public health and lost Emissions inventories must be used with care, however, as productivity should be compared with other threats-including some in-depth studies have confounded the conventional inadequate provision of safe drinking water, inadequate primary wisdom. Identifying sources of pollution is a complex process health care, and extensive use of dirty cooking fuels in homes. with major implications for policy decisions. Approaches On the basis of comparative assessment of exposure risk suitable for South Asian cities will be covered in a separate and attenuation cost, the cost-effectiveness of policies for briefing note. outdoor air pollution in saving lives and reducing illnesses should be compared to policies in other areas. What transport activities do most damage? Two sources of particles are especially visible in South Asian cities: heavy-duty diesel vehicles and two stroke engine two- Different pollutants should be ranked according to their and three-wheelers. In both cases, but particularly in the case toxicity and ambient concentrations. Available data indicate of commercial vehicles, age and poor maintenance may that the pollutants with the most damaging health impacts are concentrate the pollution impact even further. fine particulate matter (causing serious respiratory illnesses Common perceptions about mobile sources of particles can and premature deaths) throughout South Asia, and airborne be misleading. For example, a recent study in Colorado, USA, lead (which retards intellectual development of children) in showed that gasoline, and not diesel (as suggested by the Pakistan or Sri Lanka where leaded gasoline is still used. emissions inventory) vehicles were the primary contributors Does transport contribute significantly? to particles in the vehicle exhaust category [ 11. While detailed analysis of particles conducted in this study is time-consuming If outdoor air pollution is found to be serious, the next question and resource-intensive, even rudimentary carbon and other is the relative contribution of road traffic to pollution. If it is chemical analyses of particles can go a long way to supplementing an emissions inventory and enhancing 1. Increase private vehicle occupancY by such measures our understanding of contributions from different sources. as giving priority to high occupancy vehicles (lHOVs) both Figure I shows the process for such policymaking. on the roads and in parking. and developing incentives for ride sharing. Particularly where there are discrete and Selecting Policy Instruments significant hottlenecks, this approach can have substalnDial effects on individual travel decisions, and hence on If transport is a significant contributor to urban air pollution, environmental impacts of urban transport. the next step is to evaluate alternative instruments to reduce the impact. Briefly, the issue can be disaggregated in turn 2 Increase public trasport share, particularly for the into three objectives - journey to work. This not only reduces total vehicle kilometers, but also enables remaining vehicles to flow * Fewer vehicle kilometers traveled in total more freely, thus reducing emissions per vehicle kilometer. * Less fuel use per vehicle kilometer traveled Some technological measures can be helpful-segregated busways, as in Bogota, have been demonstrated to reduce * Less pollution perunitolfluel used. emissions substantially. Priority bus lanes have some. but Table I shows some of the key policy options in each category. lesser, impact. Other policies are predominantly Three important observations can be made. First, each has administrative. For example, institutional and regulatory both technical and behav,ioral com/potinents. Second. most reform to create orderly competition for franchises has transport users are subject to-and respond to- strong improved performance and maintained public transport economic and financial conistraints and incentives. Third, share in many countries. environmental improvement is likely to be more easily achieved by woring wth, rther han aginst,the eonomi 3. Restrainl use of) Private vXehicles. Use of private vehicles by wrorkinlg wizthl, ratlher tliati a,gaitist, the ecoioitic- .. .. can be limited administratively (as by the "Day-without- a-car" programs in Mexico City and Bogota). But this : ;: vehicle .... -*. :; may have the adverse side effect of causing people to retain or obtain a second car (often old and polluting) to In the long run, efforts at reducing emissions must be coupled escape the restraint. It is thus increasingly recognized that with decreasing demand for motorized transport. Three main such schemes need to be supported by economic thrusts may be effective. measures. An important step is to try to ensure that private Figure 1. Flow Chart for Evaluating Transport-Related Policy Options Is the health impact of outdoor air pollution serious compared to that from other sources such as lack of access to clean water. adequate health care, and to clean cooking and heating fuels? Yes ffi No => Look for incremental opportunities in transport policy (see text on page 1) Which pollutants cause the most damage to public health on account of toxicity and elevated concentrations? Fine particulate matter Lead => Eliminate lead in gasoline Is tranlsport a significant conitributor to high amnbient concentrations offine particuilate mlatter, or are other sources (small stationary sources such as diesel generators. refuse burning, wood burning, and coal burning: background dust; industrial emissions) combined much more important? Yes No * Look for incremental opportunities in transport policy (see text) Which vehicle and fuel combinations are likely to be responsible? iesel Gasoline Heavy-duty Medium- and light-duty Four-stroke Two-stroke U Table 1. A Framework for Selecting Instruments Technological Administrative Economic REDL'UN(G VEHICLE KILONIETERMS Increase private vehicle High occupancy vehicle lanes Congestion pricing occupancy Parking priority to HOVs Encouraged car sharing Restrain demand Vehicle use limitation; parking Road pricing, fuel tax, parking policies pricing; taxing vehicles by distance run Increase public transport Dedicated busways Bus priorities Subsidy to public transport share Public transport regulatory reform REDUCING FITEL LSED) I'ER EHIlCCLE KILONETER Improve fuel economy Increase engine efficiency Fuel economy standards Fuel taxation Reduce vehicle size Encourage NMT Investment in NMT Protection of NMT in road infrastructure use Improve traffic management Intelligent traffic system technology REDUCING ENMISSIONS PER LINIT OF FlUEL USED Improve fuel quality Tighter diesel fuel standards Differential taxation Bans on leaded gasoline Improve vehicle maintenance Age restriction on vehicles Differential vehicle taxation I/M programs and fines Improve conventional diesel Four stroke; electronic fuel Tighter emission standards technology injection; oxidation catalyst for in-use vehicles (with diesel containing 0.05% Diesel sulfur reduction to sulfur or less) enable catalyst adoption Improve two- and three- Higher quality lubricant for Tighter 2T lubricant standards Differential taxation wheeler technology two-stroke engine Ban new two stroke-engines Four-stroke engine Tighter two/three-wheeler Pre-mix fuels for two-strokes emission standards Use alternative fuels Investment in CNG Much tighter PM standards Differential fuel and vehicle distribution Mandate use of gas taxation Switch to "clean diesel" Ultra-low sulfur fuel (0.005% Much tighter PM standards Higher tax on conventional technology or less) and particulate trap diesel vehicle users pay fully for all the costs incurred, including South Asian countries could benefit from setting charges pollution, congestion and damage to roads. Although for use that reflect costs. correctly charging for these "external" costs is complicated by their location- and time-specific nature, such charges Using less fuel per vehicle kilometer are already being implemented in cities such as Singapore Fuel taxation is the strongest instrument here. While it may and Seoul, as well as in some developed countries. not induce those who have private cars to use public transit', U in some developed countries it has discouraged less essential and vehicular emission standards trips, reduced trip lengths and encouraged purchase of higher should be technically consistent. Institutional anzd fuel economy vehicles. Vehicle taxes and annual license fees For example, it does not make regulatory reform that are based on pollution characteristics could further be sense to mandate oxidation to create orderly used to prevent over-use of polluting vehicles. catalysts in diesel vehicles if the . . ElimZinating impediments to noinnotorized transpor-t (NMT) level of sulfur in diesel is above coinpetitli for by providing adequate sidewalks and bicycle lanes, and 0.05 percent, as sulfate-based franchises has assuring the safety of pedestrians and cyclists can also deter particu-late emissions will improved the use of cars, particularly for the short trips which are on increase initially and catalysts performanice average the most polluting (because of high pollution at start will be poisoned gradually by and mainitained up and at very low speeds). sulfur. * Aoptonof he es avilale pulblic transport Generating less pollution per unit of fuel Adoptie n of ts belstd c saillte share in manzy Many governments see the solution to transport generated effrctive in developing country countries. air pollution primarily as one of technological clean-up. In cities with a large number of some respects this is right. For example, elimniniation of lead poorly maintained vehicles. Upgrading maintenance in gasoline is an important and effective step that practices and replacing the worst engines should be governments can take, both because of the relative ease and considered first before moving on to better technology. low cost with which lead removal can be implemented, and *Manctlatinig az specific technology or filel chloice is a because of the heavy environmental imipact of leaded fuel. *mandating a tpe t-enology or-ffechicessa Bangladesh, India and Nepal are lead-free today. move that should not be taken lightly. Cost-effectiveness. and technical, economic and social sustainability should In South Asia, emphasis tends to be put, rightly, on the be carefully considered. For example, mandating catalytic reduction of particulate emissions. The policy debate has converters when gasoline is known to be routinely ,ometimnes focused narrowly on the question of replacinc, cnetr hngslnei nw ob otnl so adulterated with kerosene may lead to short catalyst life. diesel by cleaner altematives. most notably compressed natural gas (CNG). If a cheap source of natural gas exists (as in Inconsidering policies,governmentsshouldthuslooknot northern Bolivia) and a distribution infrastructure for gas exists only at administrative enforcement of technological as in Argentina) this may indeed be the appropriate policy to altematives but at fuller policy packages. To assist that II'tLlic. Even so, replacing diesel with natural gas has run consideration, this briefing note will be supplemented by into difficulties worldwide because of unfavorable inter-fuel further notes on international experience with CNG itaxation: diesel is not taxed sufficiently, so that CNG cannot vehicles: public transport policies to reduce air pollution: compete with diesel in the long run on economic grounds. taxation instruments: and traffic management to reduce This presents a serious challenge to the promotion of CNG pollution. as a diesel replacement in South Asia. If, in addition. alternative fuels are expensive, the economic cost of conversion can be Note very high and it may be more cost-effective to concentrate 'The cross elasticity of demand is typically 0.1 or less. on other dimensions of policy. Reference 'The Policy Implications [1] Watson, J.S., E. Fujita, J.C. Chow, B. Zielinska, Three important caveats should be noted about a technology- L. W. Richards. N. William and D. Dietrich. 1998. focused policy, namely: Nortlhern Fronlt Rcatnge Air Qualitx Studv Final Report. ' Fuel qualitY and vehicle technology shouild be treated June 30, prepared for the Office of the Vice President for togetlier as a systeln. Strengthening of fuel specifications Research and Information Technology, Colorado. This briefing note was prepared in October 2001 as part of the South Asia program on urban air quality management, funded in part by the joint UNDP/World Bank Energy Sector Management Assistance Programme (ESMAP). The objective of the program is to support the region-wide process of developing and adopting cost-effective and realistic policies and efficient enforcement mechanisms to reverse the deteriorating trend in urban air. For further information, contact Sameer Akbar (sakbar@worldbank.org), Ken Gwilliam (kgwilliam@ worldbank.org) or Masami Kojima (mkojima@worldbank.org).