In Print: The End of Automobile Dependence: How Cities Are Moving Beyond Car-Based Planning

Amid the ongoing debates over climate change, considerations of “peak auto” have eclipsed those of “peak oil” in recent years. In this cautiously optimistic book, the former notion is updated and aligned within a set of long-term strategies necessary to achieve a low-carbon green economy. Although many aspects of the authors’ prognoses are hopeful, the book’s basic premise is flawed.

Peter Newman has been an outspoken critic of auto dependence since the oil crisis of the 1970s, and he is well known in his native Australia for his pivotal role in the rail revival of Perth. His previous work, Resilient Cities: Responding to Peak Oil and Climate Change (cowritten with Timothy Beatley and Heather Boyer), was favorably reviewed by this writer in 2010. He and Jeffrey Kenworthy are renowned among global transport experts, having rigorously compiled and published comparative data for almost five decades. This book is the last in their trilogy on the rise and fall of the auto dynasty.

Relying heavily on the latest results of their Global Cities database, Newman and Kenworthy reveal that the first signs of a decline in automobile use are finally emerging, a consequence of many variables, the most representative being downward shifts in mode share and annual auto miles traveled. They also cite such gains as the resurgence of light rail and bus rapid transit lines, low-emission cars, bike-sharing and car-sharing schemes, market demand for denser forms of urbanism, and the blossoming of transit-oriented design districts.

Continued government regulation and investment, consumer behavioral change, and technological improvements could further signal an accelerated transition to reduce global greenhouse gas emissions by 2050 to a level not exceeding 80 percent of the 1990 level. This is a fundamental green-economy objective shared by both the European Union and the Obama administration.

The authors’ yardstick for the end to auto dependence is simple enough—“when 75 percent or less of the total annual [per-capita metropolitan] travel is by car.” Scores of cities in Europe, along with Hong Kong and Singapore, are already well beyond this percentage. Admittedly, this would be a very tough sell in the United States and Australia, where car use still amounts to 95 percent of travel in metro areas, while public investment in transit and other forms of urban mobility such as biking and walking is trifling.

But the big idea behind the authors’ aspirations, one that is referenced throughout the text, is a somewhat obscure economic concept one might call the “decoupling premise.” It is a model that has been hotly debated for decades. Decoupling refers to a decline in ecological intensity per unit of economic output, and it can be defined at two levels: relative and absolute.

Relative decoupling is when the environmental impact of economic activity (carbon dioxide emissions, extraction of metal ores, manufacture and assembly of motor vehicles, etc.) grows at a lesser rate than the gross domestic product (GDP). Newman and Kenworthy’s projections and those of the European Union are based on the relative model.

However, many other authorities disagree, including environmentalist guru Bill McKibben, economist and Nobel Prize laureate Robert Solow, and Tim Jackson, a former economics commissioner for the Sustainable Development Commission in the United Kingdom. They advocate for absolute decoupling. In his widely acclaimed book, Prosperity without Growth (2009), Jackson argues that the 2050 goal is not achievable if it is based on the assumption of a perpetual increase in GDP, because the unintended consequence of such increases is continued environmental degradation. Zero growth, therefore, is the only realistic basis for planetary survival.

Newman and Kenworthy’s 45-year accumulation of data, exhaustive and detailed as it is, does engender a margin of hope for the future. And this book is unique in distilling important findings from their treasure trove of metrics. But their projections fail to make a convincing case for long-term global stability.

Martin Zimmerman directs the Green Mobility Planning Studio USA in Charlotte, North Carolina.