Margi Bradway noticed something peculiar when she went on a biking trip last year. Before her friends got on their bikes, they all pulled out smartphones. “Everyone was clicking on their Strava,” she recalls. Bradway, the active transportation policy lead at the Oregon Department of Transportation (ODOT) at the time, had an idea. Could data collected by Strava, a popular GPS-powered app that lets cyclists and runners log workouts and commutes, make her home city of Portland a safer place for bike-riders?

Portland is already a better city than most for cyclists: Hawthorne Bridge, one of the city’s five bike-friendly bridges, averages 1.7 million bike trips a year, and the city boasts 300 miles of bike lanes. But Portland relies on a very rudimentary method for collecting data on cyclists and the trips they make: volunteers count riders at various intersections around the city. Without better information, it’s difficult to improve on what already exists.