6 of the Greenest Roads in America
Where’s the greenest road in the world? Not the one lined with the most trees—the one that’s actually good at addressing pollution problems.
The recently completed $6.7 million road project in Kirkland, Washington, tops the rankings, according to Greenroads Foundation, a nonprofit that evaluates roads worldwide. It includes an 880-foot extension of the city’s 120th Street, and it rated the highest ever on Greenroads’ environmental checklist thanks to design features including LED streetlights, naturally filtered stormwater basins, and recycled asphalt.
Why does it even matter for a road—something designed to facilitate safe passage for carbon-emitting vehicles—be green?
“Roads aren’t going away anytime soon,” Steve Muench, a civil engineer at the University of Washington, told KUOW. “To ignore that is missing a huge opportunity to improve the community and the environment around these things.”
The Kirkland project is the 21st to receive Greenroads’ “Silver Road” certification, scoring the highest total ever—48 points out of a possible 118.
The road scored so high for a variety of reasons, Greenroads— Jamie Holter said. A few standouts:
- The road extension eliminated unnecessary stopping at four signals, reducing carbon emissions in the process.
- Trees planted over drainage areas actually clean the water as it percolates into the underground vault.
- The underground vault stores 270,000 gallons and manages runoff into nearby Totem Lake.
- The warm-mix asphalt used on the street gives it a 40-year life cycle, meaning repaving will not be needed.
- 20 percent of the asphalt used to make the road was recycled.
Here are five other U.S. roads that are striving to be as green as they are black.
Bagby Street, Houston
- “Rain gardens” installed along the side of the road manage heavy Texas-size storms, treating 33 percent of stormwater runoff through its bioswales (29,600 gallons).
- Used “fly ash” concrete (made from residue from the combustion of ground or powdered coal) that avoided 300 tons of carbon dioxide getting into the air.
- Installed cool pavement slabs, using regional and recycled materials that reduce and reflect heat.
- Improved walkability with in-street lighting.
Presidio Parkway, San Francisco
- The reconstruction project provided the southern access point to the Golden Gate Bridge, upgrading seismically and structurally deficient roadways.
- Project teams went above and beyond to reduce environmental impact during construction.
- Throughout the project, alternative access for bikes, pedestrians, and hikers was maintained.
Meador Kansas Ellis Trail, Bellingham, Washington
- A housing development nearby was tossing out 400 porcelain toilets, which the road crew ended up grinding up and using in its concrete pavement mix. That saved the toilets from ending up in a landfill.
- The porous pavement naturally treats runoff and provides effective stormwater management.
- Installation of low-energy LED street lighting.
Bristol Street, Santa Ana, California
- The major corridor improvement project included adding a 2,600-foot bioswale along the roadside that treats runoff during storms and reduces the square footage of impervious asphalt.
- Used old car tires and recycled asphalt in paving, saving money too.
Cheney Stadium, Tacoma, Washington
- The parking lot reconstruction project for Tacoma’s AAA Rainiers baseball team included the laying of pervious asphalt, which allows water to drain through pavement and cleans it as well.
- A large bioswale was constructed in the middle of the lot where all the water could drain efficiently and be cleaned by the natural landscaping.
- The bioswale worked so well, Tacoma did not have to add to its existing water treatment plant to manage runoff from Cheney Stadium.