By Noah Nemmers, PE

civil-engineeringAs pavement technology continues to change and advance, a major emphasis is being put on environmental stewardship. Highway administration’s efforts are increasingly aimed at the industry’s overall use of recycled materials, environmental and ecological constrains, as well as the Long-Term Pavement Performance. Better determining the current condition of the country’s pavements will serve as a roadmap for where we go next in continuing to advance and implement today’s array of pavement technology, and in achieving our ultimate goal of sustainable and longer-lasting pavements. In order for designers to truly address the issues and needs in creating a sustainable pavement design, a good set of guidelines is needed.

Martina Soderfund, whose thesis paper sparked the Greenroads project, suggests six categories for sustainable design consideration and use in developing a rating system:

1. Sustainable Alignment

For most roads, cost of construction is the highest priority determinate of path.  However, including this category in the consideration of sustainability ratings would add additional points for roads that avoided certain habitat types, such as wetlands, forests, farmlands, or other ecologically sensitive areas.

2. Materials and Resources

Asphalt, gravel, and tar have a high environmental footprint due to extraction, transportation, and use.  The materials and resources category would reward projects that made efforts to reduce these impacts.

3. Stormwater Management

Seldom recognized by the general public, the continually increasing percentage of impervious land cover has negative implications for stormwater runoff and management.  Promoting stormwater quality and quantity control through this category increases awareness of road impact and encourages the use of pervious surfaces.

4. Energy and Environmental Control

This category addresses some of the more subtle and inherent effects of typical roadway design.  It evaluates the quality of design, while considering effects on light pollution, the heat island effect, quieter pavements, eco-viaducts (wildlife and fauna crossings), visual quality, and pedestrian/bicyclist access.

5. Construction Activities

The temporary activities of the roadway construction are a major source of pollution, waste, energy use, and health issues.  Major concerns of this section can be categorized as: site disturbance, waste materials generation, noise pollution, emissions & energy usage, and the health of workers.

6. Innovation and Design

The credit definition of the last section is awarded for additional performance above the requirements set in the previous sections.  Consider it extra credit or bonus points for exceptional performance in a particular category.

The Sustainable Highway concept project tries to solve the same issues of decreasing greenhouse gases and improving air quality by changing the roads rather than the cars that drive on them. The Sustainable Highway concept is a lightweight, laminated glass canopy above the roadway that filters dust particles from the roadway before releasing air into the atmosphere. The canopy is also equipped with solar panels that produce clean energy and decrease carbon monoxide emissions.

Regardless of how high of a priority sustainability is becoming, we will be using roads for years to come.  Instead of throwing up our hands in defeat at the environmental impact they produce, forward thinkers encourage attempts to mitigate impacts.

For more information or assistance on your next roadway project, contact or (303) 940-9966.