IN THE grand scheme of things, potholes may seem like a trivial problem. But tell that to the many mayors and local politicians whose success is judged by their ability to keep roads free of them. One such, Alfonse D’Amato, an American politician, was nicknamed “Senator Pothole” by his grateful constituents.
Most potholes start as small cracks in a road’s surface, which allow water to seep in. In winter, when the water freezes, it expands, widening the crack. If the water repeatedly thaws and refreezes, the hole can grow quickly, especially since cars will worsen the damage as they drive over it. Small potholes are a nuisance; big ones can damage cars, and even cause fatal accidents.
Better, then, to fix them while they are still small. In practice, that is tricky. In America, for instance, both state and federal governments find potholes by manually examining video footage of the country’s 4.12m miles of roads. That is both expensive and laborious. Officials in Kansas City have come up with a better idea. As Bob Bennett, its chief innovation officer, describes, the city is using a mix of sensors and computer algorithms to work out where potholes are most likely to form. Mr Bennett reckons his new system can anticipate potholes with a success rate of about 85%. Having a list of likely trouble spots means less need to spend money on surveillance, which allows the city’s road-maintenance budget to stretch about 30% further than before.
Kansas City’s innovation was borne of necessity, says Mr Bennett. Like many cities, it is strapped for cash. Its road-maintenance budget is enough to repair about 4% of the city’s 6,400 miles of roads each year, but that is far short of the roughly 10% that actually need fixing. So, in collaboration with Xaqt, a small firm based in Chicago, Mr Bennett put cameras onto traffic-light poles and buried pressure sensors into the road across the 51 city blocks with the heaviest volume of traffic. Xaqt combines data from those sensors with meteorological information such as temperature, precipitation and the like. That stew of data is seasoned further with information such as the date on which the road was last repaired, the type of asphalt used, whether the road lies on a bus route, and whether it has proved prone to potholes in the past. The scheme has been so successful that Mr Bennett hopes to extend the sensors and the statistical model to the entire city.
The next step is to combine such systems with data provided by cars themselves. A number of firms, including Ford and Jaguar Land Rover, are developing ways of using forward-facing cameras (which are increasingly common on new cars) to detect potholes, in order to adjust the car’s suspension before it hits them. Given that such cars will also be connected to the internet, they could pass such data on to local highway-maintenance departments. Senator Pothole retired in 1999. Automation may do his successors out of a job.