How Things Work: Solar technology could power hazard-free ‘smart’ roads

Dylan Mori Jan 24, 2011

We, as Pittsburghers, are no strangers to snow. Many upperclassmen fondly remember the three days of canceled classes last February, while the rest of Pittsburgh raged against the poor safety conditions of the roads and the lack of plowing. Almost 12 months later, the eastern United States has experienced a series of crippling blizzards. The complaints of citizens in New York City and Atlanta, Ga. echoed those of Pittsburghers, as dangerous conditions ruined travel for many Americans. New research, however, suggests that solar power may be the answer to making the roads safer for driving and reducing the need for road-clearing crews.

The focal points of this new research are “smart” roads, which would utilize heat energy to melt snow and ice on the roads. According to a feature article on the CNN Tech website, these roads would work like giant solar cells, with large glass panels replacing traditional asphalt.

An article in the Oct. 6, 2009 issue of Scientific American describes the prototype, which consists of 1024 modules sandwiched between a layer of glass and a conducting material. The new “smart” roads would be self-cleaning, water resistant, and would contain heating elements that would keep them ice-free. In addition to melting snow on the roads, the solar cells could tap into an untouched source of energy. The absorbed solar energy could be channeled and used worldwide, reducing global carbon emissions.

The engineer behind the project, Scott Brusaw, is in the process of developing a new type of glass with increased strength and consistent traction. Collaborating with researchers at the University of Dayton and Pennsylvania State University, he will attempt to synthesize a stronger type of glass, since “glass, especially when fused together in layers, is stronger than most people think.” He also estimates the average absorption of sunlight, even when intercepted by traffic, will be at the minimum 50 percent.

The issue has also crossed into the political world. On Brusaw’s website, he discusses what he perceives as the failures of the highway infrastructure, blaming the lack of highway construction and maintenance costs, along with higher oil prices, which “have raised the cost of asphalt and diesel fuel needed to power road-building equipment.”

Others are also supportive of infrastructure reform. According to a speech given by New York City Mayor Michael Bloomberg, which was also broadcast on CNN, he praised the workers of the sanitation department for their timely response to the winter storm, but conceded that the success should be viewed as “an opportunity to do better the next time.... We always want to improve, and in every case it’s going to be a different situation.”

The Federal Highway Administration and Virginia’s Department of Transportation granted Brusaw $100,000 for research and have devoted money and resources to similar research groups around the country.

Critics have slammed the plan by pointing to its hefty price: $4.4 million per mile. These costs are in addition to the already immense price of the research, which the Scientific American article estimates at $15 to 25 million over three to five years, and unknown future costs of repairs and upgrades. The efficiency of light absorption has also been questioned, since the roads would require a texture to allow tires to grip, but the texture may reduce the amount of light absorbed.

Other self-heating options have also been explored. Rajib Mallik of the Worcester Polytechnic Institute has conducted research in freeze-resistant fluids in pipes that run alongside the pavement. The fluid would be heated during the warmer seasons and stored in nearby buildings, and during the colder seasons, the fluid would warm the streets. But for now, this promising research is a step toward shifting to greener practices.