Image courtesy of Access Magazine
In the latest issue of Access Mark Delucchi and Kenneth Kurani have figured out a solution to all our transportation problems. Okay, maybe not quite every last one. But, they do offer a radical new design for cities that would lessen the safety and pollution problems created by excess vehicle travel (aka, how we get around most cities today).
The concept centers around the idea of a two-road network. In two-road cities, one street network would be dedicated to pedestrians, bikes, mopeds, golf carts, and other "low-speed, low-mass vehicles (LLM). The other would serve cars, vans, trucks, and the rest of the "fast, heavy vehicle" inventory (FHV). By separating LLMs from FHVs, walking, biking and other sustainable forms of travel become safer and easier, leading to environmental benefits in the form of reduced vehicle miles traveled. At the same time, the FHV network becomes more efficient, because it isn't required to carry the high volumes of traffic it does today.
Delucchi and Kurani acknowledge that they aren't the first to consider the idea of separating transportation modes in this way. They point to work by William Garrison at UC Berkeley, but if you read this post about the history of the sidewalk you'll see that the idea has been around much longer than that.
Leonardo Da Vinci's vision for a two-road system, circa the late 1400s
Nonetheless, the two-road network idea has yet to gain much traction in the real world. Delucchi and Kurani note that some cities have managed to at least partially implement the system (Davis in California, Houten in the Netherlands). But they suggest that future cities could be constructed around this pattern, particularly in developing countries that are expanding quickly into green space. Using the two-road system could help these countries become more sustainable, even as they embrace the automobile.
As incomes rise in places like India and China, people are driving more and more. This is already creating serious problems for pedestrians in those countries (and everyone else impacted by pollution from driving). A two-road network is one way to reduce pedestrian injuries while potentially lowering pollution from vehicle travel.