Portland enlists big data to make biking safer

Can data from fitness app Strava give Portland planners insight into cyclists' habits?


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.

The Department of Transportation licensed a data set of 17,700 riders and 400,000 bike trips

Strava might change that. Late last year, ODOT licensed a Strava metro data set of 17,700 riders and 400,000 bike trips around Portland. That adds up to 5 million BMTs (bicycle miles traveled) logged in 2013 alone. The data is now being parsed as ODOT determines what kinds of infrastructure needs that information reveals.

Though some members of the Strava community have expressed privacy concerns, company co-founder and president Michael Horvath says that most riders are enthused about the partnership. Horvath points out that every user has the choice to opt out of the program, and that rider data "has been disaggregated and anonymized" to protect identities.

Strava 1 Big

For now, the system’s biggest challenge is sample bias. To use Strava, one must own a smartphone, a technology that isn’t affordable for everyone. "People being counted by Strava are those who already have a powerful voice in bicycle advocacy and whose needs are already well on their way to being met," says Elly Blue, Portland resident and author of Bikenomics: How Bicycling Can Save the Economy.

Bradway and the department know the Strava data set isn’t perfect. "But don’t let perfect be the enemy of the good," she says. Meanwhile, municipalities around the world are taking note of Portland’s progress: Strava has already partnered with 15 other cities — including Orlando and London — on similar programs. "I think it shows that the data that we’re collecting on cycling, running, and other forms of physical activity can really inform and educate," Horvath says. "I’d like to see it in every major [city], and even small cities around the world."