Instead of wrinkles, when a highway ages you start to see cracks and potholes. While they may feel like bumps in the road, some of them can do serious damage to your car.
Kelvin Wang, a civil engineer at the University of Arkansas, researches highway cracking and other types of road damage. He says, "Cracked pavement can deteriorate real fast into pavement with a lot of potholes, and that can lead into further deterioration to total failure."
So who's checking up on the road? Wang says that while roads have evolved over time, much of the technology to check their health has not. According to Wang, most states have equipment to capture images of the road. Workers then go through the images and manually rate the severity of the pavement cracks. This is an incredibly labor-intensive task and hard to track over many years. Other states use teams of employees who head out onto the roadways and physically check the state of the road.
This diverse approach to the problem creates varying standards of pavement conditions from state-to-state. According to Rick Bennett at the New York Department of Transportation, "There are probably 50 different ways of doing it."
So Wang's company, WayLink Systems, in collaboration with the University of Arkansas created a vehicle that scans the pavement with lasers rather than conventional cameras. Wang says that the lasers consistently produce a clear image, "When you take a picture with a camera, you have to have good lighting. The laser shines on the pavement at a very narrow spectrum. The camera only can see that information."
Regular film and digital cameras are dependent on light to produce photos. The light from the sun, or an artificial light source, bounces off an object and enters the camera through the lens. Lasers contain a much more focused and organized type of light, so with the use of a special filtered camera, Wang's vehicle can take images of the road surface in the day or evening, regardless of whether it's cloudy or extremely sunny.
As he writes in the "Journal of Infrastructure Systems," the lasers can detect cracks down to one millimeter wide while driving at regular highway speeds. That's like spotting a blade of grass on the road while going 60 miles an hour.
The resulting images are immediately analyzed, the cracks are categorized, and all of the information is automatically arranged into a spreadsheet for highway engineers. The system can be expensive, with some versions costing up to $1 million. However, Wang says, because it's automated, it could save taxpayer money in the long run.
Wang's team is currently working on improving the system's accuracy. "The system has a limitation. We cannot find 100 percent [of the] cracks. It is not possible for humans and machines," he says.
In the end, he sees his technology as improving the health of our nation's roadways. According to Wang, many people are surprised to hear that many states still have people staring at cracks in the road. He says, "Most people in the world see us as the technology leader. If you tell people that even today, most agencies in the U.S. cannot find cracks automatically, they would think, 'Hm, and you can send people to the moon?'"