Drainage is important in sustainable design. In Tacoma, Wash., this roadside drainage swale keeps
exhaust byproducts, such as residual hydrocarbon compounds and heavy metals from the pavement surface, out
of water supplies. Natural bacteria in soil neutralize products in runoff prior to runoff reaching existing aquifer.

The building industry uses the LEED system to evaluate the degree of “green” design a structure or development incorporates. The LEED Green Building Rating System is a voluntary third-party rating system in which credits are earned for satisfying specified green building criteria. Projects are evaluated within five environmental categories: Sustainable Sites, Water Efficiency, Energy and Atmosphere, Materials and Resources, and Indoor Environmental Quality. Certified, Silver, Gold and Platinum levels of green building certification are awarded, based on the total credits earned.

In 2009 LEED was expanded to include complete residential developments, encompassing drives, pavements and parking areas where inclusion of reclaimed asphalt pavement (RAP) and recycled concrete aggregate (RCA) can boost sustainability points. This LEED-NR (for Neighborhood Development) rating system integrates the principles of smart growth, urbanism and green building into the first national rating system for sustainable neighborhood design.

In February 2012, the Meador Kansas Ellis Trail Project in Bellingham, Wash., became the first-ever project to achieve Greenroads certification. This project – actually a six-block area of downtown Bellingham – was reviewed by the Greenroads Foundation as an independent third party, and was certified to meet Greenroads Silver certification.

The City of Bellingham incorporated many sustainable elements into the project’s design, including recycled porcelain aggregates made from more than 400 crushed toilets that were diverted from a landfill; asphalt with recycled content of 30 percent and recycled concrete aggregates; porous pavements that naturally treat runoff and provide effective stormwater management; low-energy LED street lighting; and new amenities and improvements for pedestrians and bicycles using the Whatcom Creek Trail.

An international standard, the Greenroads Rating System is a collection of sustainable roadway design and construction best practices that address concerns about water, environment, access, community impact, construction practices and materials. There are 11 project requirements that must be completed in order for a roadway to be considered a “greenroad,” as well as 37 voluntary credits that a project team can choose to pursue.

After a rigorous review process, the Greenroads Foundation then assigns a project score based on the number of points earned by meeting the requirements and achieving credits. If certification is attained this score translates to one of the four certification levels.

“The Greenroads Rating System can be used to help manage, improve and communicate sustainability,” Muench said. “It represents an independent verification of sustainable features that truly matter and make a difference.”

Globally, 12 projects are currently pursuing Greenroads certification, ranging from new construction to reconstruction to overlay and bridge projects. Registration for project certification became available in 2011. More information is available at www.greenroads.org.

FHWA Rolls Out INVEST

The INVEST sustainable pavements rating system was rolled out in October. INVEST is a voluntary, web-based self-evaluation tool for assessing sustainability during the lifecycle of a transportation project or program. It addresses project environmental sustainability from system and project planning, through design and construction, to operations and maintenance.

INVEST 1.0 – which was radically changed from an initial 1.0 pilot version – was released via webinar on October 10. For sustainability to be fully integrated into highway and transit programs, FHWA says, it must be considered throughout the project lifecycle. Therefore INVEST focuses on three fundamental themes in agency operations: System Planning and Processes, Project Development, and Transportation Systems Management, Operations and Maintenance.

“INVEST is Federal Highway’s tool to encourage sustainability,” said Heather Holsinger, environmental protection specialist in FHWA’s Office of Planning, Environment and Realty, also at the National Pavement Preservation Conference in Nashville. “It’s a web-based, voluntary, and is not mandatory. It looks at project development through public planning, through design and construction, and finally through operations and maintenance.”