Moving closer to green: the transportation vision of Projjal Dutta

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When most people in the United States hear the word “sustainability” in relation to transportation, they immediately (and guiltily) think of high carbon emissions, traffic congestion, the impending end of the world and, most likely, odd-looking hybrid vehicles. What emerges is an image of transportation as something that inevitably adds to pollution and environmental crisis— transportation as part of the problem, rather than part of the solution.

Projjal Dutta believes that transportation, specifically public rapid-transit, is a large part of the energy solution. As the Director of Sustainability Initiatives at the MTA, Mr. Dutta is in charge of making the MTA more “environmentally, socially, and economically sustainable.” This means making the MTA more efficient and able to withstand the effects of climate change, such as the excessive flooding in August of 2007. But it also means changing the way people view and use public transportation, in New York, in the United States, and in the world as a whole.

When Mr. Dutta came to visit us in the City Atlas office, we were bracing ourselves for the traditional “you waste a lot, and want a lot” speech. And it came… kind of. Mr. Dutta showed us a comparative map of energy consumption. The numbers were shocking, even given our expectations.


The United States consumes a ton of energy per capita: measured a different way, in 2005, U.S. per capita consumption was around 340 MBtus (British thermal units, a traditional unit of energy equal to about 1.055 KJoules). Compare this to Germany’s 178, or India’s 14, and you can see that the U.S. is a distinctly heavy consumer of energy. (Japan, not shown, is about 152 MBtus per capita.)

If you look at New York City though, the per capita energy consumption is a little more than a quarter of the national average, coming in at around 88.5 MBtus.

That’s still not great, but it’s a heck of a lot better than Texas’ 496. The really shocking thing though was the energy breakdown. The World Resources Institute in 2005 showed that Germany spent around 27 percent of its energy consumption on transportation. In the United States, almost half of energy consumption was from transportation. 

Mr. Dutta explained that this disparity of energy use has a lot to do with density. Americans love suburbs. Take a low-rise suburban office park and a tall urban building. The high-rise can accommodate just as many people as the entire office park, and consumes less energy in terms of building operations (heating, etc) and materials. But the real difference is in the energy costs of transportation. The majority of people who work in the low-rise office park commute to work using single occupancy vehicles. That’s so much energy expended on transportation!

Density breeds carbon efficiency. Not only is it easier to save energy on maintenance and construction, but it also means that everyone is closer to everything. You don’t have to drive to get to the store, and your kids use the subway to get to school. Mr. Dutta showed us that in the United States, transportation generates approximately 40 percent of all green-house gases, with most of this coming from single occupancy vehicles. On a per-passenger basis, emissions coming from single occupancy vehicles are up to five times  higher than the per-passenger mile emissions of mass transit.

Public transit’s contribution to overall carbon avoidance has three key factors. Mode shift, from single occupancy transportation to rapid mass transit. By using public transit, we avoid single occupancy vehicle use and the emissions coming from that. Land use— local mass transit allows for the elimination of parking lots, as well as leading to higher density communities, allowing for shorter commutes and sometimes eliminating the need for vehicles altogether. And congestion— the decrease of vehicle traffic due to a good mass transit system allows for the vehicles that are still on the road to run more efficiently, decreasing total greenhouse gas emissions. Having an effective and efficient mass transit system allows for increased density, but also encourages increased density. Mr. Dutta had pictures of areas that, over the twenty years following the installation of a rapid transit system, developed significantly. This finding detracts from the idea that it’s useless to build service lines to less-populated areas. It’s the field of dreams, transportation edition: if you build it, they will come. And it’s really true.

Mr. Dutta’s presentation left City Atlas with many conclusions, and a lot to think about. The main takeaways were that New York City has done a great job in terms of carbon avoidance: we’ve broken out of the automobile paradigm, and the related wasteful suburban sprawl. Sure, maybe this happened all by accident (it has been noted that NYC’s density and layout occurred largely as a result of a failure of urban planning), but it still makes the city exceptional. And, looking at the breakdown of energy consumption in the United States, it’s really clear that improving the way in which we move is key. We can build a ton of “green buildings,” but it’s also important that people get to these buildings in ways other than commuting in single-occupancy vehicles.

The world is urbanizing, and rapidly. Other U.S. cities need to embrace rapid mass transit as a way to support density and sustainable growth. America should set the example of what sustainable cities look like. We have the resources; we just need the will. Cities need to embrace rapid transit as a solution, and improve existing transportation systems. We can’t wait for some future date to make rapid transit a global reality. Everyone kind of knows this in the back of their brains, but Mr. Dutta’s working to bring efficient and effective public transit to the forefront of cities’ agendas. And people have a lot of changing to do, too. We need to stop thinking of public transit as a last resort, or something that is only for lower-income people who can’t afford cars. New York is a great example of public-transit-gone-right. Here, public transit is cheap, green, convenient, and for everyone. Now: the rest of the country, and the world.

Read more about Projjal Dutta’s work at and City Atlas’ interview here, follow his Twitter @projjal, and check out his blog: