
People rarely dispute that Americans love their cars or that our infrastructure is built around them. However, what to do about these problems is a source of debate. In their book, Creating Green Roadways: Integrating Cultural, Natural, and Visual Resources into Transportation, James L. Sipes, ASLA, and Matthew L. Sipes offer up practical design and construction advice on how we can move beyond basic transportation. Sipes and Sipes, a landscape architect and engineer respectively, haven’t just written a book about roads. As they say in their introduction, they’ve written a book about “pedestrians and bicycle facilities, streetscapes, community character; protecting cultural and natural resources and ensuring creatures large and small can cross the road safely. It is about multimodality, natural processes, and energy efficiency.”
With common language, thorough research and numerous case studies, the Sipes provide the reader with sound arguments for making our roadways green. They define green roadways as highways and roads that are site specific, that respect both the visual character of the place as well as plant and animal life. Green roadways work with a site’s watershed, maintain green corridors, and protect open spaces. It is possible, the authors maintain, to create roads that both meet traditional engineering standards and minimize their impact on the environment. More than that, though, green roadways are about getting people out of their cars – walking, biking and using public transportation.

They contend that the time is ripe for this green conversion, citing quite a few scary statistics: 33 percent of our nation’s roadways are in “poor or mediocre” condition; 36 percent of our major urban highways are congested; and 26 percent of bridges are “structurally deficient or functionally obsolete.” They point to the collapse of the I-35 W bridge over the Mississippi in Minneapolis as an example of what might happen if we don’t make these changes. And not to put too fine a point on it, since the book has gone to press, yet another bridge has collapsed, this time on I-5 over the Skagit River in Washington State.
The number of cars on our roads has quadrupled from 65 million cars and trucks in 1955 to 246 million today, and where in 1970 vehicles in the US traveled 1 trillion miles per year, in 2010 that number had increased to 3 trillion miles per year while the amount of paved roads increased only 1.97 percent. These numbers are staggering, and the basic argument that the Sipes make is that building more roads won’t solve these problems. After all, how will laying down more roadways provide a solution when we can’t maintain what we have? Instead, their book makes a strong case for integrating roads, bridges, trails, walkways and other elements so they become assets, not liabilities. As they say, “roads and highways have such an impact on our communities that we need to start thinking about them in terms of quality of life.”
In urban and suburban areas, especially on local and neighborhood roads, the move should be on “de-emphasizing roads.” They should be narrowed and their visual impact lessened, sidewalks widened, and opportunities for sociability increased. The use of rain gardens and bioswales rather than a reliance on drains also lessens the environmental impact of roads.


Greener roundabouts can be used to slow traffic, and in the case of the roundabout in Normal, Illinois, it was designed as a community gathering places as well as a system for underground storm water collection.

Our interstates can be retrofitted to allow for wildlife crossings, either as land bridges or underpasses, which protect habitat and wildlife populations that live around highways. The authors note that the average cost of repair to a vehicle after a crash involving an animal is $2,900, a figure that certainly makes these changes worthwhile.

Both Sipes, who do believe there is still a place for pleasure driving, especially along the nation’s scenic and historic roads, provide the reader with examples of roads that are done well. They also offer recommendations for protecting the environmental, cultural and historical resources along these roadways.


The authors are dedicated to turning our transportation systems to assets, not liabilities, and have written a book to help guide this transformation.
This guest post is by Heidi Petersen, Student ASLA, ASLA 2013 summer intern and Master’s of Landscape Architecture candidate, Illinois Institute of Technology (IIT).
Excellent information we have needed for decades. See Interstate 35 in Downtown Duluth, MN
How exciting to read that people are getting more and more excited about “de-emphasizing roads” and actually making our roadways green! Are we actually hoping to return to little social communtities where people gather together to chat, walk and ride bicycles? Perhaps an area where people can gather by a little cafe to play chess and say hello to those passing by them on the paths? I long for that time. I have never been fond of huge highways.
My curiosity is perked with the terms bioswales and rain gardens. I would love to hear more about them. We have had a lot of rain lately here in Michigan. I would love to know how to use it, so that it doesn’t gather uncontrolled in my back yard which slopes down to a very shaded area. Gardens just keep evolving, like people.
Thank you for sharing.
Environmental mitigation for roadways is a great idea (although not a long-term solution). However, the abstract above implies that “green” roadways, with underground stormwater collection systems (hardly a natural process) require less maintenance. Maintenance of any underground system is relatively high (assuming it does not get ignored altogether). I hope the book at least mentions the primary causes of the growing number of miles driven — constant U.S. economic and population growth. In 1955 and 1970, the U.S. population was 165 million and 205 million, respectively. Today the U.S. is at more than 316 million.
Though I generally agree with the views presented, I must point out that it’s disingenuous to point to the 35W and I-5 bridge collapses as examples of an aging infrastructure. The 35W collapse was due to a design flaw (steel gusset plates 1/2 the required thickness), and I understand the I-5 collapse was due to an over-height truck striking the bridge structure. In each of these cases, the age and upkeep of the structures was not a major factor in the collapse.
Let’s not forget about parking lots and their impact on urban sprawl. Every time I am on Google Earth I look at the suburban parking lots, that are typically 90% empty, and wonder why planning ordinances don’t limit the amount of off-street parking instead of requiring excessive minimums. The green renovation of urban and suburban streets should be the focus of our national transportation policy related to the automobile, not the expansion of rural highways.