DOT: Citi Bikes Are Nearly 30 Percent of Bicycle Traffic in Bike-Share Zone

Most Citi Bike users ride bike-share for work or errands. Photo: John Wisniewski/Flickr
Most Citi Bike users ride bike-share for work or errands. Photo: John Wisniewski/Flickr

This afternoon, DOT released a bunch of data about Citi Bike ridership that gives some new insight into how New Yorkers are using the system, which covers Manhattan below 60th Street and parts of Brooklyn. The Citi Bike data also informs a new estimate of how many bicyclists are on the street in this part of the city.

DOT estimates that on a typical day there are about 113,000 bike trips each day within the bike-share zone: 33,000 (29 percent) on bike-share, and the remaining 80,000 on private bicycles. The estimate is based on DOT’s counts of Citi Bikes and other bikes at 10 locations within the service area in August, using the ratio to extrapolate the total number of non-Citi-Bike trips in the bike-share zone.

Some context: The number of daily Citi Bike trips is about ten times higher than East River Ferry ridership, which served approximately 3,000 people a day in 2012. DOT noted that 113,000 trips per day is equal to the combined ridership of Manhattan’s two busiest bus routes — the M15 on First and Second Avenues and the M14 crosstown on 14th Street. It is also equal to 29 percent of the total number of yellow taxi trips originating within the bike-share service area, the agency says.

DOT also surveyed 1,038 bike-share users in August and gathered information about how and why they use the system. Citi Bike is overwhelmingly used for utilitarian trips, not recreation: 54 percent used it for work trips, including commuting, while a third used Citi Bike to run errands. Only 14 percent used it for sightseeing, while 12 percent used it for exercise. (Respondents could choose more than one option.)

Nearly two-thirds of users said they had replaced subway trips with bike-share and 63 percent said they have used Citi Bike when they otherwise would have walked. Trips by taxi, livery, and personal car were also replaced with bike-share: 21 percent of users said they have hopped on a Citi Bike instead of taking a car. Only 18 percent said they would have taken the bus, while nine percent said they would have used their own bike. Importantly, many trips are supplementing other modes, not completely substituting for them: 52 percent say they combine Citi Bike with other modes of transportation (like transit or taxis) some or most of the time.

Citi Bike has also led New Yorkers to parts of the city they would not otherwise explore: 46 percent said they had used bike-share to go somewhere they wouldn’t have gone without it.

Because the bike count data was calculated from the total number of Citi Bike trips, it offers the most solid estimate yet of total cycling activity within the bike-share zone. DOT’s regular screenline counts of cyclists at key points, such as the East River bridges, are best used for figuring out year-over-year growth trends, not total cycling activity.

Based on survey and Census data covering the whole city, DOT estimates that there are 311,000 bike trips each day in the five boroughs (when combined with Citi Bike, that number rises to 342,000 daily), and that 54,000 of these bike trips, or about 17 percent, are to and from work. The agency says it used data from a 2011 Department of Health and Mental Hygiene survey and the 2009-2011 Census Bureau American Community Survey to arrive at these estimates. Getting a solid estimate of citywide biking has been a tricky problem to solve; we have a query pending with DOT about the methodology for the five-borough figures.

Update: A spokesperson explained how DOT reached their citywide estimate extrapolating from the Department of Health survey:

Based on their results, DOH data indicated 4.9% of the adult population biked in last week. DOT used this percentage, the city’s adult population, the average number of biking days found in the DOH survey (3.47), and an estimated two trips per day to reach our estimate.

  • Kevin Love

    If 29% of the bicycle traffic is on bike share, and only 9% of them were from people who switched from a private bicycle, that means that the bicycle mode share just jumped 26% due to Citi Bike alone. Impressive.

    Based upon the experience in other cities, bike share also has the effect of boosting private bike use. Bike share provides an easy low-cost way of trying cycling, and many people go on to buy their own bike.

    And that’s only after six months! Bike share looks like a game-changer. It will be fascinating to see what the performance has been a year from now.

  • 42apples

    I think this shows that bike-share is not really a great environmental initiative (only 20% would have taken cars instead, and there are pretty environmental costs significant costs to the infrastructure and trucking bikes back and forth). Rather, it is a convenient benefit that supplants existing public transit and is more convenient than walking.

  • Greg Costikyan

    But supplanting subway and bus rides, particularly during rush hour, is also a benefit, as it reduces crowding and likely has a secondary effect of inducing more mass transit users. Also, while mass transit is unquestionably more green than automobiles, it still involves the consumption of electricity or diesel fuel (rail produces only about half as many emissions per mile travelled than cars), so there is a (lesser) environmental benefit here.

  • 42apples

    True, but many bike share trips are replacing walking, which is the greenest mode of transportation. In that case, it makes transportation more time efficient, but not more environmentally efficient. I support it personally because I like biking and if I end up living and/or working in a city, I would feel better using it than having to lock up my bike.

    On another note, since bike share is so widely used as an alternative to light rail or subway, why don’t they offer a per-trip rate too for the same price as transit or even less? If I remember, some European cities charge that way.

  • Jonathan R

    Kevin, I wish! But the denominator for mode share is the total of all travelers, so the increase of 30k in bicycling is just a drop in the bucket compared to subway, bus, taxi, and private motor vehicle.

  • Anxiously Awaiting Bikeshare

    But it is the percent change of a percentage. Like how a 50% increase from 2% is 3% (not 52%).

  • Dave Barman

    There is no incentive for being environmentally aware. There is huge incentive for convenience, efficiency, and cost savings. Let’s remember, any successful initiative will not be successful for environmental reasons. It has to make sense for the economic incentive first.

  • Jonathan R

    Considering how most mode-share calculations neglect how folks regularly use multiple modes to get on their way, this is not necessarily the case. Folks who are using bike share to get to a more convenient subway stop might not show up in mode share calculations as bicyclists.

    Certainly true that more people are bicycling, but that seems to be a fairly obvious result of placing several thousand easy-to-rent bikes out on the streets.

    I urge immediate expansion of bike share to neighborhoods around the city in order to bring the same opportunities for bicycling to all New Yorkers. The current area is not enough.

  • StepUpAndSaySomething

    You might say “only 20%” but to me that sounds like a lot of car trips avoided and a lot of pollution that wasn’t put info our kids lungs.

    I agree that the rebalancing takes energy, but hopefully as the system matures these issues will decrease. Maybe instead of growing by zones into areas that have people commuting into Manhattan, we grow in paths, so people can get around their own communities, like further out in the outer boroughs. There are lots of opportunities to decrease car trips there. Fixing the “last mile” issue is major there.

    I hope that the friends and families of the new riders become more engaged in street safety issues. Every cop/politician with a daughter or son who uses bike share will be more likely to bust cars acting aggressively. And safer streets means less cars. In the long term, I think the numbers will show amazing environmental impact.

  • Ian Turner

    Unfortunately, from a pollution or congestion perspective, mode shift is unlikely to have much impact. Congestion and parking are the two greatest disincentives to driving, so if you convince some people to switch to another mode, others will just take their place.

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