The Greening of Our Cars is Oversold

I have long thought that the greening of our cars will have little or no impact on the total problem. In fact, I think it will make congestion worse, since emissions-guilt will no long play a role.

Michael Replogle says it brilliantly: "The forecast growth in motor vehicle traffic--60% over the next two decades in the U.S. and many times that in China and India--threatens to overwhelm gains won through increasing vehicle fuel efficiency." Here's the whole article...


Solutions Michael Replogle 03.19.08, 6:00 AM ET

There is huge potential for fuel-efficient cars and low-carbon fuels to reduce transportation's impact on climate change and public health. But technological developments alone won't be enough to solve these problems.

A key arena for innovation will be finding ways to grow the world's communities and economies while at the same time reducing how much driving the population is doing. The forecast growth in motor vehicle traffic--60% over the next two decades in the U.S. and many times that in China and India--threatens to overwhelm gains won through increasing vehicle fuel efficiency.

Unfortunately, some techno-fixes like biofuels, electric vehicles and hydrogen-fueled transportation have been oversold. While they hold long-term promise, truly green versions of these options are still many years away from delivering major pollution reductions. Managing traffic will not only curb CO2 but also make cities more economically efficient, healthy and livable.

The key to success is to keep car traffic from growing to unsustainable levels to begin with. A 2007 Urban Land Institute study found that shifting two-thirds of new U.S. growth to compact neighborhoods where cars are not the only transportation option would save 85 million tons of CO2 annually by 2030. That figure is more than the combined annual emissions of over 16 million regular passenger cars.

California's San Joaquin Valley recently adopted financial incentives to encourage developers to design subdivisions that reduce the need to drive. This helps cut emissions while providing better choices for consumers and reducing costs overall.

Most cities would also benefit from bus rapid transit systems that delivers high-speed, high-capacity, flexible public transportation at a fraction of the cost and time, while serving many more destinations than traditional rail transit.

Getting incentives right for drivers and commuters is also important, and there is plenty of precedent. London and Stockholm have cut greenhouse-gas emissions from vehicles in their city centers by 15% with congestion pricing (charging motorists to enter the central area during peak hours). Germany charges trucks with dirty engines higher tolls on its nationwide Autobahn network with GPS satellite toll collection.

This has doubled the rate at which old vehicles are replaced by new, clean ones. Pay-as-you-drive insurance, which rewards drivers who drive less by setting premiums by the mile, could reduce Americans' driving by 10% or more.

On a growing number of roads from Singapore to San Diego, tolls are being adjusted by the time of day to ensure roads operate efficiently without congestion, with revenues funding better public transportation. New information feedback systems are optimizing passenger and freight routings. In Yorkshire, England, performance contracts tie the road manager's earnings to how well traffic moves.

Traffic management is powerful. But maximizing its benefits will require the right incentives, such as rewarding carbon reductions equally--whether they come from greener cars or smarter infrastructure. In the end, shrinking our carbon footprint will require better infrastructure, expanded low-impact travel choices and incentives for wise consumption and stewardship of the resources that get us from here to there.

Michael Replogle is transportation director of the Environmental Defense Fund.