How bike share is changing American cities

Ten years ago, bike share was a novelty in the U.S., with a few thousand bikes in operation. Today, there are 55 systems spread across across the country, with over 42,000 bikes available in cities of all sizes. Over the same decade, however, traffic congestion and vehicle miles have increased faster than ever. So how much is bike share really changing how we get around?

The National Association of City Transportation Officials (NACTO) has compiled the most comprehensive bike share study to date, looking at the number of bikes, trips, and systems. The facts prove something you’ve probably witnessed first-hand: U.S. bike share culture is growing at an astounding rate.

But not just the number of systems that’s grown—the dramatic increase in bike share ridership is also notable. Compared to just five years ago, the number of bike share trips nationwide have increased from 2.3 million to over 28 million.

Most of the trips—85 percent—are taken within just five big systems: Citi Bike in New York, Capital Bikeshare in D.C. Citi Bike in Miami, Divvy in Chicago, and Hubway in Boston. And of those cities, New York’s Citi Bike is fueling most of the year-on-year growth. But a total of 28 million rides per year on what’s essentially a brand-new mode of transport for cities is a significant number of trips. (Although the U.S. is lagging far behind China’s numbers.)

While the growth is impressive, the data leads to more questions about how we’re choosing to move. Are bike share systems getting people out of cars and reducing the negative effects of vehicles in general? The answer seems to be: Sometimes. It really depends on the city.

A recent NYU Rudin Center for Transportation study showed that in New York, for example, Citi Bike is mostly being used to shorten commute times: most trips are under 10 minutes and the busiest stations are located around transit hubs. As Curbed NY put it, Citi Bike fills in the gaps that are “too long to walk but seem too short for a subway trip.” Which may have even contributed to the dip in subway ridership last year.

Using bike share as a “subway replacer” is common for big cities, which have an extremely high density of stations to complement robust public transit networks. A 2014 study that looked at bike share habits in Washington D.C. found exactly that: D.C. rides are most likely to take the place of a train or a bus segment (especially on a nice day), but not really car trips.

So what happens in a bike share city that’s less dense and more car-dependent, especially now that on-demand apps make summoning a car so easy?

Biketown

Portland’s Biketown bike share launched in July of 2016, and about six months in, evidence suggests it’s removing cars from streets. A recent survey of Biketown users by the Portland Bureau of Transportation reported that up to a quarter of rides—26 percent—are replacing what would have been a car trip. For older, more established systems, that number may go up even higher. Earlier this year, Denver’s B-Cycle, which opened in 2011, reported that almost half of its 2016 trips—47 percent—replaced car trips, even though overall ridership went down last year.

What’s more interesting is looking at the types of trips that are being replaced. A University of Pittsburgh-Carnegie Mellon study that looked at Healthy Ride, Pittsburgh’s bike share that opened in 2015, examined ride behavior in a different way: Did bike share systems help decrease the demand for parking? The researchers compared bike docking data with parking meter data for a particular neighborhood before and after Healthy Ride arrived.

While the reduction wasn’t groundbreaking—parking demand only went down two percent, or 69 rides, once bike share went in—the researchers found something even more notable: The average distance traveled by either mode was an easily bikeable .85 miles. If two percent of travelers had already shifted, the trend could continue.

But it turns out the shift from one mode to another is more dependent on what happens around those bike share stations: Do riders have a safe place to ride?

NACTO’s ridership data from seven U.S. cities shows that as cities build better bike infrastructure, which includes bike share systems, ridership goes up. But those systems are only capturing a tiny percentage of potential riders in the cities they serve. A 2012 Oregon Transportation Research & Education Consortium study showed that 60 percent of people are “interested but concerned” in riding bikes, and 81 percent of those would only ride on streets that had a protected bike lane. Philadelphia saw a 79 percent increase in bike commuters to its downtown since 2010 after adding bike share, better mapping, and protected lanes.

That’s why bike share systems can’t just put some bikes on the curb and hope riders will show up. They must be accompanied by a targeted buildout of the city’s bike infrastructure. And as a Shared-Use Mobility Center report noted last year, they also must be part of a multimodal network that provides options for every trip.

Even with the increase of bike share ridership across the country, only one person has died while using a bike share system in the U.S., which is an astounding statistic. That doesn’t just illustrate the fact that streets become safer as more people shift from car to bike. It’s because streets optimized for biking are designed to move everyone—drivers, bikers, walkers—slower, visibly, and more safely towards their destinations.