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A Global High Shift Scenario: Impacts And Potential For More Public Transport, Walking, And Cycling With Lower Car Use

Posted by Content Coordinator on Thursday, September 18th, 2014



Executive Summary

This report is the first study to examine how major changes in urban transport investments worldwide would affect urban passenger transport emissions as well as mobility by different income groups. It starts with the most recent United Nations urban population forecasts and the most recent model framework and forecasts used by the International Energy Agency (IEA) for global mobility modeling. The study extends these with new research on the extent of various urban passenger transport systems in cities across the world, as well as new estimates of the extent of mobility by non-motorized transport and low power e-bikes.

The study considers two main future scenarios: a baseline urban scenario calibrated to the IEA 2012 Energy Technology Perspectives 4° Scenario and a newly developed alternative scenario called “High Shift” (HS), with far greater urban passenger travel by clean public transport and non-motorized modes than in the Baseline and a decrease in the rates of road construction, parking garages and other ways in which car ownership is encouraged.

The study concludes that this High Shift scenario could save over $100 trillion in public and private capital and operating costs of urban transportation between now and 2050 and eliminate about 1.7 gigatons of carbon dioxide (CO2) annually – a 40 percent reduction of urban passenger transport emissions — by 2050. This suggests one of the more affordable ways to cut global warming pollution is to design cities to give people clean options for using public transportation, walking and cycling. In recent years transportation, driven by rapid growth in car use, has been the fastest growing source of CO2 in the world.

Transportation in urban areas accounted for about 2.3 gigatons of CO2 in 2010, almost one quarter of carbon emissions from all parts of the transportation sector. Rapid urbanization— especially in fast developing countries like China and India—will cause these emissions to nearly double worldwide by 2050 without changes in policy and investments.

Among the many countries and regions examined in this global study, three stand out:

United States: Currently the world leader in urban passenger transportation COemissions, with 670 megatons annually, the US is projected to lower these emissions to 560 megatons by 2050 because  of slower population growth, higher fuel efficiencies, and the decline in driving per person that has already started as people move back to cities. But this pace can be sharply accelerated with more sustainable transportation, dropping by half to 280 megatons, under the “High Shift” (HS) scenario. For the U.S. in particular this scenario includes not only mode shifting, but also considerable reductions in urban kilometers of travel per person through urban re-centralization and substitution of telecommunications for travel.

China: CO2 emissions from transportation are expected to mushroom from less than 200 megatons annually today to nearly 1200 megatons (1.2 gigatons) in 2050, due in large part to the explosive growth of China’s urban areas, the growing wealth of Chinese consumers, and their dependence on automobiles. But this increase can be slashed to fewer than 700 megatons under the “High Shift” scenario, in which cities develop extensive BRT and metro systems. Total kilometers of travel do not drop significantly for China in HS. The latest data show China is already sharply increasing investments in public transport.

India: CO2 emissions are expected to leap from about 70 megatons today to over 500 megatons in 2050, also because of growing wealth and urban populations. But this increase can be moderated, to only 350 megatons, under HS, by addressing crucial infrastructure deficiencies in India’s public transport systems and slowing the growth in car use.

While this study has not focused on further actions to boost motor vehicle fuel economy, it takes into account existing policies that, in the IEA Baseline scenario, would reduce energy use by improving average new car fuel economy by 32% in the OECD and 23% in non-OECD countries. The High Shift scenario increases this to 36% and 27% respectively, due to improved in-use driving conditions and a slight shift to smaller vehicles. However, the Global Fuel Economy Initiative (www.globalfueleconomy. org) calls for much more: a 50% reduction in fuel use per kilometer for light-duty vehicles worldwide by 2030. Achieving the GEFI 2030 goal could reduce 700 megatons of CO2 annually beyond the 1,700 reduction possible from a High Shift scenario. Taken together, achieving this fuel economy goal with better public transport, walking, and cycling could cut annual urban passenger transport CO2 emissions in 2050 by 55 percent from the baseline in 2050 and 10 percent below 2010 levels. Strong fuel economy programs for other types of vehicles (medium- and heavy-duty trucks, buses, and 2-wheelers) as well as vehicle electrification and other low-carbon fuels are key complementary strategies to enable deep cuts transportation sector CO2 emissions. These options will be investigated further in relation to High Shifts in the future.

Diesel black carbon soot emissions not only contribute to climate change, but as local air pollution these emissions are a leading cause of early death, responsible for more than 3.2 million early deaths annually. Exposure to vehicle tailpipe emissions is associated with increased risk of early death from cardiopulmonary disease and lung cancer, as well as respiratory infections in children. Car and diesel exhaust also increases the risk of nonfatal health outcomes, including asthma and cardiovascular disease.

Thanks to analysis by the International Council on Clean Transportation (ICCT), this study considers the effect of motor vehicle emissions controls and changes in vehicle activity on tailpipe emissions of fine particles, or soot, and related public health impacts. While better public transport, walking and  cycling have the potential to cut air pollution; these benefits can be eroded or even reversed if buses lack the strongest emission controls. Future growth in vehicle activity could produce a four-fold increase in associated early deaths by 2050 even with a global shift to mass transit. Adoption of best-practice motor vehicle emission controls and ultralow-sulfur fuels – consistent with or better than the latest Euro 6/VI standards adopted in Europe – across most of the world could save 1.36 million early deaths annually. Cleaner buses alone would account for 20 percent of these benefits. Thus, such emission controls are a sensible part of any High Shift strategy.

Using a new methodology developed for this study to evaluate the equity impacts of changes in transportation systems, the study also assesses how these alternative scenarios might affect the mobility of people at different income levels in various countries and regions. This shows that the majority of the world’s population currently lacks access to cars and will continue to lack access even in 2050. Under the baseline scenario there would be much greater inequality of mobility than if cities develop more efficient and widespread public transportation and safe and attractive conditions for walking and cycling, as occurs under the High Shift scenario. In this scenario, mass transit access would more than triple for the lowest income groups and more than double for the second lowest groups. Notably, overall mobility (kilometers per person per year) evens out between income groups to 2050 compared to the Baseline, providing those more impoverished with better access to employment and services that can improve their family livelihoods.

The study concludes that unmanaged growth in motor vehicle use threatens to exacerbate growing income inequality and environmental ills, while more sustainable transport delivers access for all, reducing these ills. This report’s findings should help support wider agreement on climate policy, where costs and equity of the cleanup burden between rich and poor countries are key issues.

Figure 7: Total Urban Passenger Travel for Select Countries/Regions

Figure 7: Total Urban Passenger Travel for Select Countries/Regions

Figure 8: Travel Per Capita for Select Countries/Regions

Figure 8: Travel Per Capita for Select Countries/Regions

Download full version (PDF): A Global High Shift Scenario

About the Institute for Transportation & Development Policy
The Institute for Transportation and Development Policy works with cities worldwide to bring about transport solutions that cut greenhouse gas emissions, reduce poverty, and improve the quality of urban life…Cities throughout the world, primarily in developing countries, engage ITDP to provide technical advice on improving their transport systems. ITDP uses its know-how to influence policy and raise awareness globally of the role sustainable transport plays in tackling green house gas emissions, poverty and social inequality. This combination of pragmatic delivery with influencing policy and public attitudes defines our approach. Most recently, ITDP has been instrumental in designing and building the best bus rapid transit systems in the world.

About University of California, Davis
With a mission to advance the human condition through improving the quality of life for all, UC Davis uses a framework that connects its land-grant history to a transformative vision for the 21st century.

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