Driving the Sustainable Highway
Green Highways, in Many Forms, Gain Credence
At first, the idea of a "green" or environmentally friendly highway might seem incongruous. After all, highways and the machines that use them are among the largest users of energy and of many other resources as well.
However, a wave of experiments and innovations are aiming, in a variety of ways, to make highways less energy intensive and perhaps even modest contributors to a more ecologically sound environment. Those approaches range from a green highway that is spanning the west coast with charging stations for electric vehicles, to a host of state and local initiatives, many in the east, that focus more on enhancing and protecting the natural environment in and near the highway right of way.
In the Pacific Northwest, the Washington State Department of Transportation and the Oregon Department of Transportation have teamed up to create the West Coast Electric Highway, which consists of a network of electric vehicle direct-current fast charging stations located every 25 to 50 miles along Interstate 5 and some of the other major roadways in the region. The electric highway is a key element in the West Coast Green Highway, which aims to promote cleaner fuels, especially along the 1,350 miles [2160 km] of Interstate 5, which has been designated a "Corridor of the Future" by the U.S. Department of Transportation.
According to Tonia Buell, project development and communications manager for public-private partnerships at the Washington State Department of Transportation, the electric highway provides assurance to drivers of electric vehicles that they will be able to get a "refill" at many points along popular routes, making travelling longer distances from home more practical.
The initiative, still expanding to the south through California to Mexico and to the north into British Columbia, Canada, is already robust enough to have supported a "BC to BC" (British Columbia to Baja California, Mexico) demonstration by nine drivers, who were all able to make the lengthy journey without using a drop of liquid fuel. According to Buell, including the facilities of the electric highway, the West Coast as a whole, has a robust EV charging network with thousands of charging pedestals and dozens of DC fast chargers. However, Buell notes, there is a disconnect: Not all manufacturers use the same connectors or the same kinds of batteries and voltages, making it harder for an infrastructure program to match the needs of all plug-in electric vehicles. For the moment, she explains, the program is trying to please as many users as possible.
Meanwhile, in other parts of the country, the green highway focus is more literally on things that are green - emphasizing better management of plants, cutting impacts on wildlife and, additionally, seeking ways to make highways more efficient and less energy intensive.
For example, Florida's state landscape architect, Jeff Caster, introduced the management of the state department of transportation to the idea that the actions of the department could better support pollinating insects, critical to the state's agricultural sector, as well as other green goals. Initially his suggestions were greeted with considerable skepticism.
However, Caster was able to make a convincing case that simple steps - such as mowing grassy margins less frequently, especially when flowers were in bloom - could not only help bees and other insects, but also reduce labor, fuel and capital costs associated with more frequent mowing.
According to Caster, Florida's program has so far taken only modest steps. But, trotting out a favorite statistic, namely that the DOT manages some 186,000 acres [750 km2], which amounts to about 0.5 percent of Florida's total area, he notes, "our landscape touches everyone."
Armed with that insight, Caster says the state is thinking along three lines - supporting ecological systems, reducing DOT energy use, and supporting pollinators that, in turn, support the state's farmers.
Virginia has embraced a more ambitious green highway agenda. According to Andrew S. Alden, director, smart road operations at the Virginia Tech Transportation Institute, and coordinator of the Virginia Green Highway Initiative, with the help of federal funding, programs span a wide range, with a particular focus on developing standards for a wireless infrastructure. "We have built two test beds for a new system called Connected Vehicle, which is a kind of internet for transportation that provides for communication between vehicles, and between vehicles and infrastructure," he notes. The goal of Connected Vehicle is to make highways safer and more efficient; better managing traffic, warning of hazards, and even alerting drivers to animals crossing a roadway.
The potential of the system is wide-ranging, Alden notes. Trucks may be able to gather and use information about slopes and traffic to sustain more efficient operations and, like a smart phone, Connected Vehicle could spawn an app industry, helping to create even more uses for the underlying technology.
In short, the movement is "going to town." As Jolly notes, "green highways are at the heart of everything we do."
Alan R. Earls is a writer and author who covers business and technology topics for newspapers, magazines and websites. He is based near Boston, Mass.
ASTM and the Sustainable Roadway
ASTM International technical committees are engaged in developing standards that impact sustainable roadway infrastructure.
- Subcommittee D04.99 on Sustainable Asphalt Pavement Materials and Construction, part of ASTM Committee D04 on Road and Paving Materials, is developing standards involving sustainable bituminous materials and construction that consider and improve environmental impact.
- The use of recycled materials in highway construction is also the focus of Subcommittee D18.14 on Geotechnics of Sustainable Construction, part of ASTM Committee D18 on Soil and Rock, which is developing standards for using industrial byproducts together with earth materials for sustainable infrastructure construction.
- Subcommittee C09.24 on Supplementary Cementitious Materials, part of Committee C09 on Concrete and Concrete Aggregates, offers standards that enable the reuse of industrial materials in concrete. Similar goals are being achieved by Subcommittee C09.27 on Ground Slag, which develops standards for reusing ground granulated blast-furnace slag.
- ASTM International is also working with the Slag Cement Association and the Portland Cement Association to develop product category rules for slag cement and portland cement. These PCRs will eventually help manufacturers develop environmental product declarations, which provide quantifiable environmental data to compare the life cycle impact of products. This is part of a new ASTM initiative to assist diverse industries with the development of PCRs and EPDs.