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Across the entire globe, motor vehicle usage has increased tremendously. One result is that many areas of the world have been experiencing serious motor vehicle pollution problems. To deal with them, significant motor vehicle pollution control programs have become increasingly common, leading to tremendous advances in petrol car control technologies. At present, similar technologies are under intensive development for diesel cars and trucks and significant breakthroughs are starting to appear with production diesel vehicles. The purpose of this paper is to survey what is presently known about the transportation related environmental problems in Asian cities, to summarize the adverse impacts which result, to review actions underway or planned to address these problems, and to estimate future trends. Potential strategies for ameliorating transportation related environmental problems will be assessed.

Over the past century, huge amounts of air pollutants and gases have been released into the atmosphere that now pose risks to human health, natural ecosystems, and the earth's climate. Motor vehicles are a major contributor to both the build-up of greenhouse gases -- potentially the most serious of these problems -- and the creation of urban smog and acid rain. The purpose of this paper is to summarize the nature of these problems and the role played by motor vehicles in causing them. The significance of pollutants other than CO2 which are emitted in large quantities from vehicles will be shown to be important for global warming. Further, the increasing significance of vehicles produced or registered in rapidly expanding countries will be assessed. Finally, the growing importance of vehicle modes other than passenger cars will be summarized.

Worldwide concerns with global climate change and reducing oil consumption have increased interest in expanding the global light duty diesel penetration, adding to the already dominant role of diesels in commercial vehicles. The major impediment has been concern over the adverse health effects associated with diesel exhaust. This paper will review the status of these concerns, summarizing recent studies conducted by the World Health Organization, the US EPA and the California Air Resources Board. In response to these concerns, various countries have adopted controls on both diesel vehicles and engines and their fuels. The current status of these efforts as well as the state of control technology will be summarized.

At the present time, as the world's vehicle population inches over 700 million, countries around the world are continuing to struggle with their motor vehicle pollution problems. Some countries have made great progress in reducing CO and HC emissions from vehicles, and to a lesser extent NOX, in spite of substantial growth in their vehicle populations. While car standards continue to be pushed, the motor vehicle focus is gradually shifting to heavy duty trucks and buses and off road vehicles and engines. Fuels improvements are also playing an increasingly important role. Finally, concerns with CO2 and other greenhouse gases are getting increased attention. The purpose of this paper will be to provide a broad overview of these developments, highlighting the successes achieved to date and the future challenges.

Areas of rapid Industrialization in Asia are now starting to experience unacceptable air quality or are projecting that they will in the relatively near future as a result of rapid growth in their vehicle populations. In addressing these problems, there is much that can be learned from the experience and mistakes of the industrialized world. In addition, however, there are some unique problems of developing countries, especially certain of the smaller ones in Asia, which would seem to benefit from special approaches. The purpose of this paper is to briefly survey the adverse environmental impacts resulting from motor vehicles, to review technologies developed to address these problems, and to summarize the current status around the world. Special focus will be on the development of strategies to address the emerging problems of developing countries in Asia.

Across the entire globe, there has been tremendous movement toward the further control of diesel vehicle emissions over the past 1 to 2 years. With regard to heavy duty vehicles, the EU in late 1999 finalized requirements for Euro 3, Euro 4 and Euro 5, to be phased in by 2008. These requirements are expected to require the introduction of advanced PM and NOx controls. The US EPA has adopted even more stringent requirements to be introduced in 2007 along with very low sulfur (<15 PPM) diesel fuel. Japan is in the process of an intense review which will likely reduce fuel sulfur levels to at least 50 PPM and introduce substantially tighter PM requirements by 2005. They are also developing a major diesel retrofit program. With regard to light duty vehicles, the California Air Resources Board has established the principle that diesel fueled vehicles should meet the same standards as gasoline fueled vehicles and the US EPA followed suit with its Tier 2 program.

While great progress has been made over the past two decades in controlling emissions from motor vehicles, serious problems remain. Substantial growth in vehicles and poorer than expected in use performance have partially offset reductions achieved. While future gains must continue to take advantage of technological and fuel advances, special attention must be paid to in-use emissions and vehicle growth.

As the diesel population continues to grow in various parts of the world, and as concerns regarding diesel particulate effects on public health and the environment increase, more and more countries are adopting tighter and tighter standards. The purpose of this paper is to review the current status of such regulation around the world.

Driven in part by concerns regarding global warming, there is a clear trend toward increased sales of light duty diesel vehicles in many parts of the world. This trend can result in many positive environmental benefits including low fuel consumption, and therefore low levels of CO2, low levels of exhaust CO and HC (especially during cold start conditions), and very low levels of evaporative hydrocarbons. However, increased diesel sales have a downside, relatively high NOx and particulate emissions. These pollutants continue to receive high priority attention in most areas of the world. As a result, countries around the world are increasingly tightening diesel regulations with the result that technology for reducing emissions continues to advance. Engine and combustion improvements have substantially reduced NOx and particulate from modern engines.

High mileage vehicles (in excess of 50,000 miles) contribute more than half of all vehicular emissions. With the new catalytic converter equipped cars, the proportional contribution of these vehicles may be even higher than for pre-catalyst vehicles. Thus a substantial portion of motor vehicle related air pollution may be caused by vehicles not subject to the manufacturer directed provisions of the Clean Air Act. This paper presents a modeling effort based on hypotheses and some preliminary data, and suggests some alternatives to combat this potential problem.

This study builds upon the National Academy of Sciences study in the rapidly changing area of diesel particulate cost-benefit analysis and updates it where appropriate based on new data or analysis. It does not generate new information but merely reviews and analyzes existing data. The body of the paper a) explains the basis for estimating the various costs, b) describes a computer model to relate the costs to the benefits, and c) presents the results of the analysis.

This study builds upon an earlier diesel particulate cost-benefit analysis and updates it where appropriate based on new soiling and odor information. It does not generate new information but merely reviews and analyzes existing data. In addition, a new section dealing with heavy duty trucks and buses is added.

This paper examines one aspect of the in-use compliance program - recall. It reviews the existing program and its evolution, evaluates a variety of the modifications which have been suggested and proposes some specific changes which would retain the overall goals while resulting in some increased flexibility and therefore some potential cost savings compared to the existing program.

This study applies the methodology developed for two earlier evaluations of diesel particulate controls to urban buses. Since these vehicles are used almost exclusively in urban areas where population is most dense, the analysis indicates the net benefits of control are very high.

The purpose of this paper is to survey the adverse environmental impacts resulting from motor vehicles, to review technologies developed to address these problems, and to summarize the current status of pollution control programs around the world.

Rapidly industrializing developing countries are now starting to note similar air pollution problems to those of the industrialized world. This paper surveys the adverse environmental impacts resulting from motor vehicles, reviews technologies developed to address these problems, and summarizes the current status of pollution controls around the world. Special focus is on the design of strategies to address the emerging problems of developing countries.

The purpose of this paper is to review and summarize recent trends around the world regarding diesel vehicles, the health effects associated with diesel particulate, and the actions taken by governments to reduce these emissions. Further, the paper will summarize manufacturer efforts to develop control technologies for diesel particulate.

The purpose of this paper is to review and summarize recent trends around the world regarding motor vehicle pollution control. It shows the persistence of and in some cases worsening of motor vehicle related pollution problems, the increasing spread of advanced pollution control technologies including catalytic converters to address these problems, and the push to extend the capability of these advanced technologies to attain even lower pollution levels under a greater variety of actual operating conditions. As the global vehicle population continues to grow, the impact on global warming is assessed.

This is the latest in a series of papers on the subject of the costs and benefits of diesel particulate control. The initial focus was on new light duty vehicles with a gradual shift to heavy trucks and buses. This latest study considers in-use urban buses and explores the relative costs and benefits of three alternative control strategies - retrofit of trap oxidizers, introduction of inspection and maintenance and conversion to methanol fuel. It concludes that retrofit is very cost beneficial and could be made more so by the addition of I/M. Conversion to methanol results in the maximum particulate reduction but is not as cost beneficial for the particulate reduced as is retrofit.