When I was in grad school at the University of Montana back in the late 1990s, they launched a small bike sharing system as an experiment. I forget if it was Missoula-wide or just the university (Google is no help), but there were these funky green bikes with wire baskets, kept, unlocked, in wooden sheds. Anyone could take one — you were just supposed to put it back in one of the sheds. It all ran on the honor system.

And as I recall, it was a disaster. The bikes were cheap and broke down all over the place. They got abandoned, stolen, beat up. No one ever put them back in the sheds. The experiment was quickly abandoned. (If someone has a better memory and/or documentation of this peculiar historical episode, contact me!)

Ever since then, I’ve wondered when the technology of bike sharing systems would catch up to the good intentions. In theory, bike sharing offers all sorts of benefits. It makes cycling a service, available to casual commuters, people who do not wear spandex or own road bikes. It can work as a complement to a multimodal urban transit system, covering the “last mile” between transit stops and home/work. Bike trips often replace motorized vehicle trips, improving air quality and reducing carbon emissions. Plus, it’s a nice way to encourage exercise.

But it’s got to work; all the pieces have to come together to make it convenient, useful, and pleasant.

So when will that happen? The answer is: It’s happening now.

The National Association of City Transportation Officials (NACTO) has just released the first comprehensive snapshot of bike-share growth in the US. What it shows is that, from 2010 to 2016, bike sharing has gone from virtually nothing to … well, something. It is still a marginal means of transportation in the grand scheme of things, but if current growth rates hold, that won’t be true for long.

Let’s look at some of the top-line numbers.

There were 88 million total bike-share trips taken in the US between 2010 and 2016. The annual number of trips reached 28 million in 2016. (By way of comparison, there were 10.75 billion trips on public transportation in 2016.) The number of bikes has grown to 42,000.

Bike share systems are rapidly spreading. Though the concept dates back to 1965 (in Amsterdam, of course), there were only four systems in the US in 2010; there are now 55. (NACTO defines a bike-share system as “at least 10 stations and 100 bikes.”)

As the size of those dots indicates, however, the overwhelming share (85 percent) of bike-share rides are taken in a few key cities with large systems: Citi Bike in New York, Capital Bikeshare in Greater Washington DC, Citi Bike in Miami, Divvy in Chicago, and Hubway in Greater Boston.

As you can see, New York City is responsible for a lion’s share of the nation’s total bike-share riders (just as it is responsible for a lion’s share of its total transit riders).

Bike sharing systems don’t run on cheap-bikes-in-wooden-sheds any more. Most existing systems have “smart docks,” with automatic locks and digital tracking. And just about all new systems since 2014 use “smart bikes,” which have all the locking, tracking, and other digital gear onboard, making use more convenient.

Here’s a smart bike from Portland, Oregon’s Biketown system, with the keypad, screen, and lock all built in:

There have been persistent concerns about equity in bike share systems. Especially early on, they were generally marketed to and used by upscale professionals. However, more and more bike-share systems (24 percent) are offering subsidies for low-income riders.

Philadelphia’s Indego system, for instance, offers cash payment (for those without a credit card) and has begun offering subsidies for low-income riders. As a result, NACTO says, “the number of new subscribers with a household income under $35,000 using the system jumped from 27% in 2015 to 44% in 2016.”

It’s also worth noting that bike sharing systems are extremely, almost spookily, safe. My colleague Brad Plumer wrote last year that while the overall fatality rate for cycling in the US stands at 21 per 100 million trips, bike sharing fatalities currently stand at: zero. (Sadly, that is no longer current — in July 2016, bike sharing saw its first-ever fatality, in Chicago.)

NACTO emphasizes that its snapshot is only a snapshot; many existing systems are planning expansions. Houston’s B-Cycle plans to more than double its number of both bikes and stations. New York City’s Citi Bike, already the nation’s largest system, plans to go from 10,000 to 12,000 bikes and from 600 to 750 stations. Expansions are also in the works in Philadelphia, Atlanta, Phoenix/Mesa, and San Francisco/Oakland, among others.

More cities are sure to jump on the bandwagon. Bike sharing systems are almost universally popular. They typically use very little tax revenue, covering costs with sponsorships and user fees. They both complement and support public transit systems. And, of course, riding bikes just makes people happy. People could use a little happy these days.

Further reading

A while back, CityLab did a gorgeous visual history of bike sharing systems.

Sadly, my home city of Seattle is one of the few to kill a bike sharing system — a victim of poor finances, bad management, lack of ambition, and a dumb helmet law.

Bike sharing is also big internationally; you can find every system in the world on bikesharingmap.com.

Europe has 4% more cities with #bikesharing programs than Asia, Asia has 1,400% more bicycles in public use programs! #publibike pic.twitter.com/f3JQBoJhLM — The Bike-sharing Map (@BikesharingMap) February 2, 2017

In a recent story for Outside Magazine, Joe Lindsey rounded up the (admittedly still sketchy at this early stage) evidence for bike sharing’s benefits:

A 2015 study in Transport Reviews looked at systems in five cities, including Washington, D.C., and Minneapolis, and found that users substituted rides via bike shares for car trips 8 percent of the time in D.C. and almost 20 percent of the time in Minneapolis. A separate study on D.C.’s Capital Bikeshare found that it contributed a modest but noticeable 2 to 3 percent reduction in traffic congestion. And a 2014 report from the NYC Department of Transportation found that even though some traffic lanes were converted to protected bike lanes on various streets, travel times for car traffic remained steady or improved: on Eighth Avenue, they were 14 percent faster, for example. More people on bikes translates to not only less traffic congestion but also more physical activity: in excess of 23,000 hours in Minneapolis just in 2012, according to the 2015 study. Additionally, a report on London’s massive bike-share system found injury rates for bike-share users were lower than those for regular cyclists. In the U.S., there has been one bike-share rider death in the system’s seven-year history. By contrast, roughly 700 cyclists die each year on America’s roads. (There is no known cause for that disparity.) According to the same London study, even when injury rates and pollution exposure were balanced against physical activity, bike shares have a modest but net positive effect on overall public health by virtue of the physical activity. And a recent study of New York’s Citi Bike program in BMJ’s journal Injury Prevention found that the city’s addition of bike lanes, crucial to Citi Bike’s success, increased lifespan even among nonusers because of the reduction in pollution.