Greener Highways

When building and maintaining a safe and efficient surface transportation system, impacts on the natural and cultural environments are inevitable. But federal, state and local highway agencies are taking steps to integrate environmental sensitivity into their day-to-day activities, which range from recycling old pavements and protecting watersheds during construction to involving community members and business leaders in the transportation decision-making process.

In 2002, the Federal Highway Administration (FHWA) designated environmental stewardship and streamlining as one of its three "vital few" goals, along with safety and congestion mitigation.

Subsequently, FHWA made substantial investments in improving the quality and efficiency of environmental decision-making through initiatives such as context sensitive solutions (CSS), the Eco-Logical approach, the Exemplary Ecosystem Initiatives program, the recently announced Human Environment Initiatives program, and efforts to link planning and the environment.

The Green Highways Partnership is a voluntary, collaborative effort aimed at fostering partnerships to improve upon natural, built, social and environmental conditions while addressing the functional requirements of transportation infrastructure.

After initial meetings and forums, a group of 40 representatives from the public and private sectors met to frame the future of Green Highways and to refine the road map for the partnership.

The group divided into three theme-focused teams after identifying the following focus areas that offer the greatest potential to demonstrate Green Highways concepts:

• Watershed-driven stormwater management;
• Recycling and reuse; and
• Conservation and ecosystem management.

"These areas are ripe for focus because of advancements in environmental science and technology," says Robb Jolly of the American Concrete Pavement Association.

Green Highways implements pilot projects that demonstrate the concepts visibly and tangibly in the mid-Atlantic region. "Pilot projects will inform and inspire the implementation of practices and actions that are innovative, efficient, cost-effective and environmentally sound," says Veeramachaneni. "The anticipated outcome of the pilots is to demonstrate sustainable solutions and provide for market-based incentives," he continues. "Pilots also will serve to improve partnerships and research efforts. Green Highways serves as an opportunity to translate good ideas into practical realities."

The recycling and reuse team is focusing on efforts in a number of areas. First, team members are identifying existing regulations and specifications. The team then will develop state performance standards and specifications for voluntary use of recycled materials in highways.

The team also is collecting and disseminating information to increase use of recycled products and developing opportunities to exchange best practices. In addition, the team will produce a tool kit to provide technical information and guidance to help DOTs (departments of transportation) overcome hurdles.

Another priority is to identify state DOT projects that optimize the beneficial reuse of industrial byproducts. To date, Maryland, Pennsylvania, Virginia and West Virginia have been targeted for pilot projects to showcase beneficial reuses in their states.

As each state offers ongoing stewardship examples, Green Highways will help increase the visibility of these activities and increase their use on more projects. For example, the Pennsylvania DOT constructed the Tarrytown Bridge using shredded tires as lightweight embankment fill on two bridge approaches. The project incorporated approximately 780,000 scrap tires, thereby easing the load on landfills.

In West Virginia, the DOT is using recycled blast furnace slag as the aggregate of choice in the western part of the state for the majority of asphalt surface course pavements. The effort results in a safer pavement due to the aggregate’s non-polishing properties (higher friction number).

According to Jason Harrington, an asphalt pavement engineer with FHWA, with an open-graded friction in course aggregate like slag, the roadway does not experience as much spray or misting during rain, offering better visibility and much less hydroplaning.

Further, recycling slag, which is available locally in western West Virginia, offers an economic advantage compared with using virgin limestone aggregate.

"Although the coarseness in slag increases friction, which is highly desirable, the size of the aggregate [pieces] are larger, which contributes to a slight increase in noise levels. When noise is a concern, the use of smaller aggregate sizes (0-6 mm or 0-10 mm) is recommended," says Chris Corbisier, FHWA highway traffic noise specialist.

In addition to the pilot efforts under development within each theme area, the partnership is looking to apply Green Highways concepts in a more comprehensive manner. Toward that goal, the Maryland SHA recently volunteered to apply an environmental stewardship approach to a transportation improvement project by implementing the following key actions:

• Application of environmental stewardship principles in the development of alternatives retained for detailed study.
• Full integration of the regulatory requirements for avoiding and minimizing direct impacts on resources through planning and design measures and modifications.
• Incorporation of state-of-the-art features, design techniques and best management practices.
• Evaluation of overall resource conditions and identification of priority stewardship needs in consultation with project partners and public stakeholders using a watershed framework for environmental management.
• Design and implementation of plans, strategies and actions—beyond those associated with compensatory mitigation—that seek to improve the overall natural, community and cultural environments.
• Identification of a preferred alternative that furthers the project purpose, satisfies the project needs, and balances and minimizes direct, indirect and cumulative impacts on natural, community and cultural resources.

In keeping with the collaborative nature of Green Highways, SHA is planning a design charrette to investigate potential green approaches, technologies and actions. "This project will provide an opportunity to integrate all of the principles and concepts of Green Highways into a single project and has the potential to serve as a model for other projects in the mid-Atlantic and across the country," says SHA’s Veeramachaneni.

Also, Green Highways is forming a communications network that is being maintained through a Web site (www.greenighways.org), regularly scheduled leadership meetings and press events.

Among its diverse functions, the network will craft a Green Highways awards and recognition program; develop, implement and manage the pilot programs; identify and seek funding mechanisms; and act as a conduit to environmental entities at federal, state and local government levels, academia, nongovernmental organizations and trade and industry groups.

The network will coordinate outreach with organizations such as AASHTO, American Road & Transportation Builders Association and consultants.

The Green Highways Web site serves as a tool to consolidate resources, support effective communication and networking, streamline information sharing and facilitate technology transfer, according to Dominique Lueckenhoff, who is part of the Water Protection Division at the United States EPA Region 3 office. "The site will be the information ‘nerve center’ for all activities related to Green Highways," she comments.

In addition to the Web site, the partnership is pursuing other outreach activities across the mid-Atlantic to spread the word about Green Highways.

Proponents are meeting with state DOT executives across the region to explain the goals of the partnership and assess interest and opportunities within the theme areas. Further, the Transportation Research Board’s ADC10 Committee on environmental analysis in transportation is planning a Green Highways workshop for the annual TRB conference in Washington this January.

Building on innovative programs and approaches spawned from transportation and resource agencies, Green Highways will make it easier for DOTs to integrate common-sense, economically feasible solutions into their day-to-day work in planning, building and maintaining the nation’s surface transportation system.

"Partnerships like Green Highways are vital to the transportation community and can help facilitate the timely delivery of a quality transportation program," says Neil Pedersen of the Maryland SHA. "The ultimate goal of Green Highways is to develop self-sustaining public-private and public-public partnerships." C&DR