Cyclists often find themselves pedaling between huge trucks and speeding cars or stranded when protected bike lanes abruptly end at busy intersections.
Chris Cassidy moved to San Francisco in 2005. He used to cycle through Market Street, a busy downtown thoroughfare.
"It was definitely the kind of biking experience that was really only for some of the more courageous among us," he says. "You would be sharing a lane with much larger vehicles going faster than you when people were not as used to sharing the lane."
Before San Francisco, Cassidy was in Washington, D.C., where he said he was hit by taxi doors twice when he was cycling in the protected lanes.
"They just stopped, and the passenger opened the door to the bike lane," he says.
Cyclists and pedestrians often pass on knowledge about which roads or intersections to avoid through word of mouth or social media.
Now some cities and companies are experimenting with technology to record that information — which can be crucial in helping design or improve bike and pedestrian paths. And transportation planners are turning to data from apps that cyclists and runners use to track themselves.
With the exploding popularity in bikes and many millennials' distaste for driving, the need for better streets is gaining attention.
What does it take to build a bike lane?
San Francisco has a goal to eliminate traffic deaths by 2024. According to the city's "Vision Zero" report, more than half of traffic deaths in the city are pedestrians, compared to 14 percent nationally.
Cassidy, now the spokesperson for the San Francisco Biking Coalition, says enforcement and smart engineering based on data are key to reaching that goal.
"The first piece of data is where are injuries happening — where people are using streets currently and where they are doing so that is proving unsafe," he says.
Technology plays a big role in how that information is collected, says Jamie Parks, a manager with the city's Municipal Transportation Agency.
"Whether it's data analysis to look at where crashes have occurred so we can improve safety, or analyzing bicycle counts to understand where demand is, or getting feedback from the public," Parks says.
The agency has issued an annual bicycle count report for over a decade now. Initially, it had to rely on sending people to count bicycles on the streets for a two-hour period.
Last year, the department added several automated bike counters that consist of a wire loop embedded in the pavement, allowing round-the-clock data collection with more accuracy.
Alex Dodds and Emiko Atherton from Smart Growth America are championing a new way of designing streets.
"Historically roads have been built to facilitate the most number of cars as possible, and usually that means wide lanes, lots of space for cars to go faster," Dodds says. "Often planners will add a bike lane. They'll just plop it on ... it's very unsafe for everyone."
The "Complete Streets Approach" means building streets that accommodate the needs of a variety of users — drivers, cyclists, children and wheelchair users.
"It doesn't mean every roadway is outfitted with a sidewalk or a bike lane, but there is a network that allows people to travel," Atherton says. "So we start to look at patterns of how people are using roadways or what streets are bikers using."
The Department of Transportation does have national data from surveys about who walks or bikes and crash statistics, but it may not be as helpful in determining which streets are used or in measuring effectiveness of street designs.
Dodds says Smart Growth America published a report last year that examined the outcome of the Complete Streets programs.
"It was really hard for us to get answers because so few transportation agencies collect information about what happens after you added a bike lane," Dodds says. "There is just not enough data out there about who is biking, and where they are biking, and where they walk."
Technology taking a crack at data collection
Strava developed software and an app that allows cyclists and runners to track their journey and compare their achievements with others. It left the company with a huge database of how people move — and it decided to launch Strava Metro, a service that shows movement street by street. Data from users is anonymized and aggregated.
The idea started, co-founder Michael Horvath says, when an employee in the Oregon Department of Transportation, who was also a Strava user, reached out to the company. She asked if the department could use the data that Strava collected. Six months later, Horvath launched Strava Metro.
"Before you can make changes, you have to know what is going on," he says.
For example, Horvath says, Strava used the data to find out how pedestrians and cyclists get to the Tilikum Crossing, a bridge that recently opened in Portland, Ore. It helped the city figure out where it should build pathways leading to the bridge.
Strava Metro is not the only database collecting such information. The San Francisco County Transportation Authority created a CycleTracks app in 2009 to track biking route choices in the city and other cities from Austin to Toronto are using it to collect data.
According to Strava, over 2.5 million GPS-tracked activities are uploaded to its database every week from around the globe. The cost to its clients — which include state and local governments — depends on the number of Strava members in a particular area. The company charges the clients 80 cents per member for a year.
While Parks says he would love to have the data — especially about cross-platform transportation choices, he still has concerns.
"People who use the Strava app may not be representative of the average cyclist in SF," Parks says. "It might be for recreational routes."
But using technology to track demand for pedestrian or bike paths is already a leap from how engineers used to detect demand for sidewalks or pathways, Dodds says.
"Sometimes if they build a new neighborhood but they don't put in enough sidewalks, people just walk where they wish to walk ... they cut the corner and kill all the grass," she says. "That is one very straightforward way for engineers to say obviously people want a sidewalk here."
Zhai Yun Tan is a digital news intern.