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Posts about Bike Sharing

Bicycling


The biggest bikeshare station in each US city

Throughout 2014, DC and New York have jockeyed back and forth over which city's bikeshare system has the most stations in the United States. But who has the biggest stations?


New York’s 67-dock station. Photo from Google.

DC currently leads in the number of stations race, 335 to 324. But the number of stations only tells part of the story. New York's stations are vastly bigger than DC's, and by far the largest in the US.

New York's biggest station, which is outside of Penn Station, has a whopping 67 docks. It's almost 50% larger than the next city's largest station.

Here's the number of docks at the biggest station in America's main big-city bikeshare systems:

RankCityLargest stationDocks at largest station
1New YorkPenn Station67
2BostonSouth Station46
3WashingtonDupont Circle45
4ChicagoMichigan/Washington43
5MinneapolisCoffman Union and Lake/Knox32
6Miami Beach46th/Collins31
7tDenverREI27
7tSan FranciscoMarket/10th and 2nd/Townsend27

Cross-posted at BeyondDC.

Bicycling


Who needs Metro? Not (as often) Capital Bikeshare users in central neighborhoods

Regular riders of Capital Bikeshare have cut down on their use of rail and bus transit, a new study shows. This is particularly strong for those in neighborhoods a short bike ride from downtown DC.


CaBi's effect on Metrorail ridership. Images from the study. Click to see the full image.

In these maps, each circle represents one zip code in which researchers Elliot Martin and Susan Shaheen surveyed CaBi users. The number shows how many responses they got in that zip code. Red is the percentage of those people who used that mode of transit less (rail for the map above, bus below). Green is for those who used it more, while yellow is those who didn't change.


CaBi's effect on Metrobus ridership. Images from the study. Click to see the full image.

It's not only transit which riders are using less. CaBi users also have cut down on car trips and probably even replaced some walk trips with bikeshare.

This isn't necessarily bad for transit. The places where this effect are strongest also happen to be the places where transit is most congested. On the busy Metro lines at rush hour, the trains are full into downtown DC; it's just as well if fewer people are hopping onto an already-packed train at, say, Foggy Bottom.

And many of the people who ride Bikeshare still use transit some of the time. They might still ride it in bad weather, but at other times avoid it at its most congested, or at times of poor service, like the very long waits on weekends during track work.

One potential danger, though, is that if there is lower demand for service on weekends (thanks to a bicycle alternative), that could make it less likely local jurisdictions want to pay for more frequent transit service at off times, even though not everyone can substitute a bikeshare trip for a transit trip.

Meanwhile, in Minneapolis (which has much less rail transit), the study found that many people increased their usage of rail, perhaps because the bikeshare system helps them access transit much more easily.

Eric Jaffe writes in Citylab,

Overall, the maps suggest that bike-share, at least in Minneapolis and Washington, is making the entire multimodal transit network more efficient. For short trips in dense settings, bike-share just makes more sense than waiting for the subway—it's "substitutive of public transit," in the words of Martin and Shaheen. For longer trips from the outskirts, bike-share access might act as a nudge out of a car—it's "complementary to public transit."

Honestly, once I started bicycling (first with Capital Bikeshare, and then more and more with my own bike) I personally cut down significantly on using transit. But I live in a downtown-adjacent area where it's a fast bike ride to many destinations; for others, that's not the case, and transit is best for their trips. I also still ride transit some of the time.

Some people in the survey also increased their use of transit. The more transportation options people have, the more they can choose the one that best matches their needs. The road network is already quite comprehensive (though often crowded). We need to offer everyone high-quality transit and bicycling as alternatives so that they can use each when it's the best choice at that time.

Taxis


"Sharing" isn't a good term for services like Uber and Lyft. Is there a better one?

Many of the services that call themselves "sharing," like "ridesharing" (Uber, Lyft), "car sharing" (Zipcar, car2go), bikesharing (Capital Bikeshare), "home sharing" (Airbnb), and others, are not really "sharing" as we typically think of the term. Do we need up with better words to describe these new business models?


Photo by Via Tsuji on Flickr.

The "sharing economy" (early on called "collaborative consumption") is a rapidly-growing sector. Most of its businesses allow people to temporarily use some good for a fee where typically, and formerly, people would own it (like a bike, a car, or an apartment).

But many commentators have pointed out that the term "sharing," at least as we learned it as children, generally means letting people use something you have for free, not renting out something you have, and definitely not a company owning a bunch of things which it rents to people or paying someone to do work on your behalf.

Companies like Uber and Lyft have been dubbing their services "ridesharing." These companies contract with drivers who can make money by offering rides. Jason Pavluchuk from the Association for Commuter Transportation argued that calling these services "rideshare" made it harder to advocate for other models that more aptly deserve the term, like carpool and vanpool services where people actually ride together.

There's also slugging, a longstanding practice where people commuting, such as on I-95 in Virginia, pick up other people at a designated spot who are going to the same destination. (The drivers don't charge for this; they do it to get the right to use the carpool lane.)

Uber and Lyft are really new variants on taxi service. They let people use a car they might already own (though Uber is also offering loans to drivers to get new cars), but they are still doing it as a job. If you use such a service, you're not sharing someone's car; you're paying them to give you a ride.

Other companies like Sidecar have envisioned a model where people already driving from one place to another offer rides to someone who happens to be going the same way. That's a little bit more "sharing" than the app-based taxi-like services.

Services like Zipcar and Capital Bikeshare also could have somewhat more of a claim to the term "sharing." In those cases, at least, there is a pool of vehicles which multiple "members" all use together. They all pay, but basically are pooling money to have a shared resource instead of owning.

What do you think counts as sharing? Is there a better term for these services?

Bicycling


Bike sharing means more head injuries, study says? Actually, it's the opposite

The headline on an NPR blog post Friday blared, "Brain Injuries Rose In Cities After Bike-Sharing Rolled Out." It sounded horrible! A tiny graph showed a pretty clear trend, suggesting hard data behind this conclusion. As it turns out, while the authors of the study and news stories sensationalize the issue, the data show the exact opposite.


(Misleading) graph from NPR.

The paper's lead author even said that this supports the conclusion she expected all along. Only it doesn't. Instead, the data seem to show that in cities which launched bike sharing systems, bike-related traumatic injuries decreased, including head injuries.

What's wrong with the analysis

The researchers (Janessa Graves, Barry Pless, Lynne Moore, Avery Nathens, Garth Hunte, and Frederick Rivara) obtained data from trauma center records in cities that implemented public bike sharing programs (PBSPs) and control cities that did not.

The best analysis would compare the number of bike-related head injuries to the total amount of bicycling. That's because if more people bike but bicycling gets safer, you might see more injuries even if every individual cyclist's risk goes down.

If they didn't have that information, it would still be useful to just look at the total numbers of bike-related injuries or bike-related head injuries. Instead, the authors made the odd decision to look at the percentage of bike-related injuries that are head injuries.

This percentage can increase for two reasons:

  1. There are more head injuries
  2. There are fewer non-head injuries (and thus the head injuries make up a larger share)
Clearly, (1) is bad. But (2) is not.

In the paper, the authors get around this limitation by being careful to state their results in an exact fashion:

In this international study, implementation of a PBSP was associated with 14% greater risk of head injury among patients admitted to trauma centers for bicycle-related injuries.
As often happens, news stories shortened this to the very different headline, "Brain Injuries Rose In Cities After Bike-Sharing Rolled Out." But it's not just the media. The authors have also been less careful in public statements since writing the article.

NPR quoted lead author Graves saying, "Public bike-share initiatives are great wellness initiatives. But without providing helmets, we were concerned that we would see an increase in head injuries. And we did."

Only that's not what they really would see if they looked at the data more clearly.

What the numbers seem to really say

I couldn't perform an in-depth analysis similar to the study's because I don't have their dataset. However, the paper includes a table (Table 2) which lists the total numbers of head and non-head injuries in PBSP cities and control cities before and after the bike sharing program began.

That makes it possible to graph just the raw numbers of injuries for these time periods. (I adjusted the numbers for the fact that the paper's pre-implementation period spans two years and the post-implementation period only spans one.)

The overall trend is clear. For the control cities, there isn't much change in total injuries (an increase of 2%) or head injuries (4% decrease). But for the PBSP cities, head injuries decreased by 14% and total injuries decreased by 28%.

Weaknesses in the data

There are plenty of caveats to both the original study and my analysis, many based on limitations in the data.

Since the data on injuries come from emergency room records, the study only captures injuries that involve visits to the ER. The decision to go to an ER could be totally nonrandom for a whole range of injuries, and we could imagine that a large bike share program might affect whether people go or not.

Moreover, the introduction of a bike sharing program is not a discrete event. The authors had to pick a date for each city, and it's unclear how sensitive the analysis is to pushing the dates a bit in either direction. Plus, some of their dates may simply be incorrect. At least in DC, as Darren Buck pointed out, the paper lists bike sharing as starting in May 2010, when it really launched in late September 2010.

Finally, the dataset just doesn't contain a ton of cases. The authors end up with two years pre-implementation and one year post-implementation for each PBSP city, and the same length of time for control cities. They only have 5 PBSP cities and 5 control cities.

Since bike-related injuries are not incredibly common and this isn't a very long time period, it's going to be hard to identify gradual trends in the data. Bike advocates tend to focus on the need to change culture over the long term, with bike sharing as one element of that. One year after the introduction of bike sharing simply may not be long enough to see much of an effect.

Finally, the dataset suffers from the problem that it's not actually experimental data. The authors make a nice effort to deal with this by finding a matched control city for each PBSP city, but there are plenty of other differences between the paired cities other than the presence of bike sharing.

For example, the PBSP cities already had a lower incidence of total bike-related injuries before they implemented bike sharing, so it's hard to argue that they're identical to the control cities. The drop in injuries could be due to some other change in PBSP cities at the same time (DC built its first cycletracks in the same year it launched Capital Bikeshare, for example).

We have no way of knowing with this sort of analysis. And since I don't have the full dataset, I can't drill down to individual cities. But the overall trend is pretty dramatic: control cities had virtually unchanged injury rates, while PBSP cities had large drops in total bike-related injuries as well as smaller drops in head injury rates.

Conclusions

Graves has said that the authors started the study expecting to find that because bikeshare riders often don't use helmets as often as other cyclists, bikesharing systems put people at greater risk of head injuries. If we take their data at face value, instead we have evidence that bikesharing may instead decrease serious bike-related injuries, including head injuries.

That would be a big deal, because many people expected that perhaps injuries would increase, but the numbers of cyclists would increase faster, meaning bicycling got safer. The paper's data might not be correct, but if it is, then it's even better news for bike sharing: cycling went up, injuries per cyclist went down, but on top of that, total injuries went down, too.

Even if it's too soon to draw that conclusion given all the caveats listed above, it's clear that the study's authors have not shown a strong and direct relationship between new bike sharing systems and increases in bike-related head injuries. It's too bad that they have trumpeted an incorrect interpretation of their data, and that press reports have spread a false and sensationalized conclusion far and wide.

Bicycling


Baltimore starts building a real bicycle network

Baltimore transportation officials have proposed a "network of bicycle infrastructure," including the city's first-ever cycletrack. It's a big leap beyond today's incongruent sharrows and paint.


The proposed Downtown Bicycle Network. Image from Baltimore DOT.

The cycletrack will stretch 2.6 miles along Maryland Avenue and Cathedral Street, from Johns Hopkins University in the north to the convention center near the harbor. It will be installed this fall. For the city's bicycle advocates, the network represents a hope that Baltimore may start to build bicycle infrastructure on par with Washington and catapult bicycling forward in the central business district.

Will the Downtown Bicycle Network actually serve downtown?

While its name is the "Downtown Bicycle Network," the projects are mostly actually in Mt. Vernon, a neighborhood north of the central business district. The cycletrack will get a bicyclist downtown, but for now that is where the network ends.

A Pratt Street cycletrack could provide an east/west complement to the north/south Maryland Avenue cycletrack.

Pratt Street is the main artery of the business district. Because of its width and concentration of businesses, hotels, tourist attractions, facilities like the convention center, institutions like the University of Maryland, it remains the grand prize for a cycletrack. Bikemore, Baltimore's bicycle advocacy organization, is pushing this idea.


Image: Pratt Street in Baltimore. The south lane (on left) is a bus/bike lane. Photo by the author.

Officially, Baltimore's bike map lists bus/bike lanes on Pratt Street. However, these lanes are not often enforced and not comfortable for many bicyclists.

Some maps and officials also consider the Inner Harbor Promenade and the Jones Falls Trail adjacent to Pratt Street as bike facilities. But in summer, they are often packed with tourists, strollers, pedestrians, and are often impassable for bicyclists.

If not for Bixi's financial troubles, it is likely Baltimore would have a bikeshare system by this summer. Hopefully, Baltimore can use the delayed launch to continue to build a better network to support cycling. The better the infrastructure, the better bikeshare will work when it eventually launches.


Proposed bikeshare stations. Image from Baltimore DOT.

Baltimore can learn from DC and Pittsburgh

Washington is not the only nearby city for Baltimore to seek inspiration. Pittsburgh has integrated quality bike facilities along its waterfront and made connections to nearby neighborhoods. In a Pittsburgh Magazine article about the steel city's revitalized riverfront, Lisa Schroeder, president and CEO of Riverlife, likens the increased traffic along the riverfront to the growth of the regional trail network.

"The more trail that was created, the higher the number of users," she said. "We hit that momentum point along the rivers this year. People realized, 'Aha—this is a network, and I can go in all directions.'" Bill Peduto, Pittsburgh's new bicycle-friendly mayor wants his city to be in Bicycle magazine top ten US cities, despite its hilly contours.

Will the Maryland Avenue cycletrack be the first of a series of complementary projects, extensions, and improvements to Baltimore's bicycle network? The fast growth of DC's and Pittsburgh's networks make us optimistic that the Charm City will soon catch the momentum too.

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