Mapping potholes
Engineering students developed an app to track, measure road quality
A far-flung group of engineering students from schools such as MIT, Harvard and Birzeit University in the West Bank have developed an app that turns a smartphone into a tool to track potholes and measure overall road quality.
No one needs an app to confirm hitting a pothole, but this project could improve life in many ways for drivers — and everyone else.
The students’ test users have already come up with some surprising data (or not so surprising for those familiar with Boston-area streets): The roads around the Massachusetts Institute of Technology are worse than the roads around Birzeit University.
“The surface streets in Cambridge have the roughness index of a wellmaintained dirt road,” said Franz-Josef Ulm, faculty director at MIT’s Concrete Sustainability Hub, who is guiding the students in developing their app, called Carbin.
Poor road quality increases fuel consumption, Ulm said. That was on his mind a couple of years ago during an educational exchange visit to Birzeit University, one of the top engineering schools in the Middle East. Fuel is expensive there, and for some Palestinians, transportation costs rival those of rent and food. He realized that if there was a way to map road quality, drivers could plan trips that cost less and reduced wear and tear on their cars.
Although drivers don’t realize it, they compensate for poor roads by pressing a little harder on the accelerator. So to maintain a constant speed, they burn more fuel and spew out more carbon dioxide. The quality of highways has a small effect on fuel consumption, but Ulm said road quality could account for 10% to 15% of fuel use in urban settings.
Another motivation for the app? “We were frustrated trying to get road-quality data from the government,” Ulm recalled.
Engineers rate road quality using a World Bank metric, the International Roughness Index, which ideally is measured by special vans equipped with lasers to scan the road. They can cost up to $700,000.
At that price, only state transportation departments can afford them, and they usually measure only major highways. U.S. cities (and Ramallah, near Birzeit University, for that matter) rely mostly on user complaints or seat-ofthe-pants assessments by city employees.
That unscientific approach presents problems, said Glenn Engstrom, director of the National Road Research Alliance, which conducts pavement research at MnROAD, the Minnesota transportation department’s asphalt test track.
“People are far more tolerant of bad roads in urban settings because speeds are lower,” Engstrom said. He noted that apps such as Carbin could be particularly helpful in cities because those expensive vans don’t work as well in stop-and-go traffic (or in freezing weather, aka pothole season).
Accurate data is better than uesr complaints for road maintenance. The time to resurface roads is when the roughness index starts to climb, even before
drivers report problems.
“Smooth roads last longer,” Engstrom said, “and that definitely helps both the environment and our pocketbook.”
Ulm bemoaned the lack of roughness-index data to another engineering professor, Arghavan Louhghalam of the University of Massachusetts Dartmouth. It occurred to her that the accelerometers built into smartphones might be able to measure road roughness.
They assembled a team of professors and students from MIT, UMass Dartmouth, Birzeit University and University of Washington and got to work.
Carbin works best if the smartphone is attached to the vehicle in a phone holder, but it works fairly well even if the phone is simply laid flat on the car floor. Isolating movement caused by a bumpy road takes some sophisticated math, but in the end, Carbin’s estimates of road quality compare favorably with the measurements taken with those laser-equipped vans.
Data from hundreds of Carbin beta testers has been collected and mapped at FixMyRoad.us.
More and more cities and states have committed to meeting the terms of the Paris climate agreement, whether the U.S. government is a signatory or not. Data gathered by Carbin users and uploaded to FixMyRoad.us already offers a new argument for improved road-maintenance budgets: reducing carbon emissions. The student team is working on a version of Carbin that would suggest the greenest driving routes.
Eventually, Carbin could be incorporated into navigation software such as Waze or Apple Maps. But the next big step isn’t technical, it’s commercial; most of the students were to graduate this spring, and their goal was to turn their class project into a startup.
Some navigation apps already offer an “eco” option based on distance and average fuel consumption. Using Carbin, apps could factor in variables including road conditions, topography, predicted idling time and even users’ vehicles and driving styles.