Canada paved its first highway, from Toronto to Hamilton, a century ago. Film footage shows gangs of workers dumping wheelbarrows filled with gravel or cement onto the roadbed, then, on their knees, working elbow to elbow, using trowels to make a smooth and level surface. Google "First Paved Highway 1912" for a two-minute documentary glimpse of this historic event. You can count 20 or 30 workers in a single gang, showing why this kind of shovel-ready work became such a favourite of governments. In the beginning, at any rate, paving roads employed a lot of people.
Canada now has something approaching 900,000 kilometres of paved roads, the United States 6.4 million kilometres – taken together, a vast expanse of heat-absorbing surfaces. Yes, road building has changed. Work crews are smaller, paving machines bigger; and highways are faster and safer than ever. But highways fill essentially the same single, simple function they filled a hundred years ago – roads without bumps.
This could soon change. This year, U.S. inventor Scott Brusaw will build a small prototype of the world's first solar-powered, electronically controlled, glass-surfaced highway on a parking lot near his lab in the small community of Sagle, Idaho.
The U.S. government will fund the experiment, which will cost a mere $750,000 – less than the cost of paving one kilometre of road. Mr. Brusaw, an electrical engineer, will seek to demonstrate that his smart solar road panels have the capacity to convert the U.S. highway system (and, by extension, Canada's) into a huge power generator theoretically capable of producing three times as much electricity as the U.S. now consumes – and almost as much as the entire world now consumes. By Mr. Brusaw's calculations, this highway-based power generator would produce so much electricity that highways could be heated, all winter long, to 40 degrees Fahrenheit.
Could solar-powered highways really mean an end to snowplows and icy roads? Mr. Brusaw says they could. He cites the rear window in cars: A glass plate is embedded with a heating element that can "crank up to 85 degrees Fahrenheit" to clear the window of snow or ice. His solar-heated highway would be permanently heating (during winter months) at 40 degrees Fahrenheit. meaning snow wouldn't accumulate in the first place.
Mr. Brusaw's solar panels measure 12 feet by 36 feet. Mimicking the rear window in a car, the surface level is made of translucent glass, textured for traction. (Glass is 75-per-cent sand, a common enough raw material.) Beneath the surface are heating elements and an array of LEDs, light devices that move electronic data and activate sensors. At the bottom of the panel, a "base plate" distributes power as required – to the road-surface information systems, to the pavement-warming systems and to transfer of surplus electricity energy storage tanks and to the continental grid.
For the motorist, the sensor devices inside the glass panel would "paint" illuminated lane-passing lines to guide traffic and would "print" warning messages – stop, slow down – on the roadway ahead as conditions required. The messages would be calculated and confirmed every 12 feet of distance travelled. This isn't as improbable as it sounds. IBM has already shown the use of roadway sensors to deliver road-condition reports.
Based on an assumption of only four hours of sunlight a day, and only 15 per cent efficiency in the capture of solar energy, Mr. Brusaw says a continental installation of smart roadway panels would generate enough electricity to power the U.S. 24 hours a day. Much of the country's highway system is massed on the East Coast and the West Coast. Thus the "lit" (day) portion of the continent would generate enough excess electricity to power the "dark" (night) part.
Mr. Brusaw's vision is intriguing. The technical credibility of the concept itself has been demonstrated. The 2012 prototype will assess the economics of "commercializing" it. Mr. Brusaw thinks a solar-powered kilometre of highway could pay for itself in six years – but, deeply in debt, governments can't afford the up-front investment. Governments will need to take highways private – or quasi-private – to produce super-smart, solar-powered roadways. The real barrier, after all, is neither scientific nor financial. It's institutional – and, lamentably, ideological.