According to the scientific  community, our society is at an ecological tipping point. Humanity is faced with urgent decisions that will determine the health and well-being  of future generations, and the window for action is closing fast. One  key opportunity we have is to make better decisions about how we invest  in our transportation system. Will many streets remain the embodiment  of pollution and danger, or will we reclaim them as public spaces that  enhance the community?

Since the 1950s, America’s  myopic focus planning for the automobile, coupled with land use regulations  that have prevented mixed use neighborhoods, has devastated our natural  environment. Calculations by Richard T.T. Forman of Harvard University indicate that nearly 20% of the US’s land area is affected by roads  and associated vehicular traffic. Streets and parking are usually the  single largest category of impervious surface in developed areas, which  contributes to the erosion and pollution of our bodies of water. In  the United States, 87% of daily trips are by car, at an average distance  of 40 miles per day. That amount of driving causes 50% of the nation's  air pollution.

Furthermore, transportation  accounts for 1/3 of US greenhouse gas emissions, making the transportation  sector the leading US contributor to climate change. Despite more efficient  vehicles, the transportation sector used 17% more energy in 2005 than  it did in 1995; our current trend of rising vehicle miles traveled in  the US will negate, if not overwhelm, future improvements in automobile  fuel economy.

It doesn’t have to be this way. Improving our transportation  system, beginning with the street in front of your house, can prevent  the many dangers posed by climate change.

The good news is that America  is experiencing a sea change. Communities are quickly recognizing the  benefits of livable communities and a comprehensive transportation system.  Virginia, for example, recently passed  legislation aimed  at preventing cul-de-sacs in new subdivisions, which will promote connectivity  and walkability. New York City has added hundreds of miles of bike  lanes over the past few years alone. Phoenix just opened a brand new light-rail system, while Portland continues to expand theirs. San Francisco  will launch their Sunday Streets program  this spring, where several streets will be closed one day a week to  cars for sole use by pedestrians and cyclists. And our office is working  with officials and communities in upstate New York to develop a community  based transit system on one of  the state’s most congested corridors, along with many other similar  projects.

The widespread excitement about  these projects clearly demonstrates a latent demand for a new approach  to transportation in America and a strong need for higher and better  uses of the public realm. We are pleased to know that dozens more projects  like these are planned for the near future, perhaps in your community.  If your community is not active in reducing the ecological footprint  of its transportation system, perhaps you can begin the process now.

The federal government has  also signaled they are now a willing partner. The Department of Transportation  and the Department of Housing and Urban Development recently announced their Livable Communities initiative,  which will coordinate federal housing policies with federal transportation  investments to provide transportation alternatives for Americans spanning  the socioeconomic spectrum. And despite the current economic climate,  federal spending on Safe Routes to School programs is also on the rise,  as is spending on bicycle and pedestrian infrastructure. Federal Complete  Streets legislation is also pending, which, if approved,  would ensure an increase in the number of sidewalks, bike lanes, and  public space improvements across the country. Complete streets are a  commendable first step, but creating great streets requires a greater  set of partners thinking about land use, architecture, and public space  management. This type of partnership is especially important for getting  the most benefit from limited resources.

All of these large and small changes at the local, state, and federal levels are needed to reduce the ecological footprint of our transportation system. Numerous studies  and modeling efforts have revealed that walkable communities with high-quality  destinations, connected street networks and comfortable pedestrian accommodations can reduce the amount we drive by 25-60%. But aiming  to create more walkable neighborhoods also presents a greater opportunity.  If we approach the changes to our transportation system with places  in mind, we can revitalize our communities, health, economy, and overall  quality of life.