Roadmap for Free-Floating Bikeshare Research and Practice in North

TRANSPORT REVIEWS 2019, VOL. 39, NO. 6, 706–732 https://doi.org/10.1080/01441647.2019.1649318

Roadmap for free-ﬂoating bikeshare research and practice in North America Jana A. Hirsch a, Joshua Stratton-Rayner b, Meghan Wintersc, John Stehlind,e, Kate Hosfordc and Stephen J. Mooneyf aUrban Health Collaborative and Department of Epidemiology and Biostatistics, Drexel University, Philadelphia, PA, USA; bLindy Institute for Urban Innovation, Drexel University, Philadelphia, PA, USA; cFaculty of Health Sciences, Simon Fraser University, Burnaby, Canada; dSustainable Consumption Institute, University of Manchester, Manchester, UK; eNational Science Foundation Scholar, Department of Geography, University of California, Berkeley, CA, USA; fDepartment of Epidemiology, University of Washington, Seattle, WA, USA

ABSTRACT ARTICLE HISTORY The deployment of smartphone-operated, non-station-based bicycle Received 20 September 2018 fleets (“dockless” or “free-floating” bikeshare) represents a new Accepted 8 July 2019 generation of bikesharing. Users locate bikes in these free-floating KEYWORDS systems using Global Positioning Systems (GPS) and lock bikes in Bikeshare; free-floating; place at their destinations. In this paper, we review current free- fl dockless; bicycle; active oating bikesharing systems in North America and discuss priorities transportation for future research and practice. Since launching in 2017, free- floating bikeshare has expanded rapidly to encompass 200+ systems operating 40,000+ bikes within 150+ cities. In contrast with previous systems, free-floating systems operate almost exclusively using commercial “for-profit” models, amidst concerns of financial sustainability. Governance for these systems is in early stages and can include operating fees, fleet size caps, safety requirements, parking restrictions, data sharing, and equity obligations. We identify research and practice gaps within the themes of usage, equity, sharing resources, business model, and context. While some existing bikesharing literature translates to free-floating systems, novel topics arise due to the ubiquity, fluidity, and business models of these new systems. Systems have numerous obstacles to overcome for long-term sustainability, including barriers common to station-based systems: limited supportive infrastructure, equity, theft or vandalism, and funding. Other unique obstacles arise in free-floating bikeshare around parking, sidewalk right of ways, varied bicycle types, and data sharing. This review offers background in and critical reflection on the rapidly evolving free- floating bikeshare landscape, including priorities for future research and practice. If concerns can be overcome, free-floating bikeshare may provide unprecedented opportunities to bypass congested streets, encourage physical activity, and support urban sustainability.

Introduction Bikeshare—public use of a communal ﬂeet of bicycles for mobility or recreation— has seen a boom in recent years, with estimates hitting 17,960,000 bikeshare bicycles across

CONTACT Jana A. Hirsch [email protected] Urban Health Collaborative and Department of Epidemiology and Biostatistics, Drexel University, 3600 Market Street, Philadelphia, PA 19104 © 2019 Informa UK Limited, trading as Taylor & Francis Group TRANSPORT REVIEWS 707 over 1700 global cities in 2018 (DeMaio, 2018a). Bikesharing has experienced numerous shifts and changes since the first programme was launched in 1965 (Shaheen, Guzman, & Zhang, 2010). Earlier systems were categorised into three generations: a first generation identified by no payment or security features; a second generation that involved a coin deposit system; and a third generation characterised by docking systems and automated credit card payment or other tracking technologies (Parkes, Marsden, Shaheen, & Cohen, 2013; Shaheen et al., 2010). Shaheen et al. foreshadowed a fourth generation identified by “(a) flexible, clean docking stations; (b) bicycle redistribution innovations; (c) smartcard integration with other transportation modes, such as public transit and carsharing; and (d) technological advances including Global Positioning System (GPS) tracking, touch screen kiosks, and electric bikes” (Shaheen et al., 2010). The deployment of smartphone- operated, non-station-based bicycle fleets, sometimes called “dockless”,or“free- floating” bikeshare, heralds in this new generation of bikesharing. These systems allow users to locate bikes using Global Positioning Systems (GPS), and then lock bikes in place at their destination (Institute for Transportation & Development Policy, 2018). In 2017, free-floating bikeshare made its appearance in North America, expanding rapidly to operate thousands of bikes across hundreds of cities. Cities need evidence on free-floating bikeshare to implement, maintain, and manage these new systems. Identifying gaps and future research or practice paths are all critical to achieving the transportation, financial, equity, health and other stated goals of free- floating bikeshare. This paper builds upon previous discussions of bikesharing systems (Fishman, 2016; Parkes et al., 2013; Shaheen et al., 2010) to incorporate issues raised by free-floating bikeshare. It aims to establish the state of free-floating bikeshare systems in North America and identify key areas for research and practice as these systems mature. Rather than perform specific analyses, this paper creates focal areas for future analyses by summarising, synthesising, and identifying gaps within this emerging domain. We first describe current systems in North America and next highlight research and practice gaps. We conclude with a summary and recommendations for researchers and practitioners.

Methodology This study employs a multi-stage approach to researching free-floating bikeshare across North America. First, we conducted a scoping literature review to identify topics in bikesharing models that pre-dated free-floating bikeshare. As part of this process, we synthesised previous literature into themes and identified parallels or differences with free- floating bikeshare. Second, we did a scoping review of all literature related to free- floating bikeshare, in particular. Due to the relative nascence of this field, most content was grey literature, news articles, and government documents. Content was catalogued into previously identified themes, with novel themes for free-floating systems identified. Third, in July 2018 and June 2019 we extracted data on free-floating systems from company websites, or by contacting operators who did not have locations online. These data were cleaned and processed by location. Fourth, between April 2018 and July 2018 we spoke with key informants in the field. This entire process was used to outline key features of existing systems. We then used the synthesised data to shape and inform the research and practice areas presented. It is important to note that while our research process was extensive, the free-floating industry is rapidly evolving. Thus, 708 J. A. HIRSCH ET AL. emerging issues with profound industry impact, including the consolidation of many free- floating bikeshare companies and the rise of e-scooters as a mode rapidly replacing bikeshares, are not fully captured.

Description of current free-floating bikeshare activities in North America A brief history of free-floating bikeshare Modern bike sharing was pioneered in the 1960s in Amsterdam, Netherlands, and has been through several generations of operating model (Shaheen et al., 2010). The most recent generation, the app-based free-floating systems we describe here, were first devel- oped in China by ofo and Mobike in 2014 and 2015 (Zhao, Zhang, Banks, & Xiong, 2018). These systems’ initial success in Shanghai and Beijing led quickly to expansions across China and to North America. While our review focuses on North American systems, there may be important lessons from the Chinese experience of free-floating bikeshare that may transfer to a North American context. China had already been a leader in docked bikeshare systems when free-floating ver- sions were introduced. In response to urban expansion in the twenty-first century, along with the increasing prevalence of private motor vehicles as the dominant transportation mode, bikeshare became popular as a way to build on the nation’s long familiarity with bicycling for congestion and pollution mitigation (Zhang, Zhang, Duan, & Bryde, 2015). Docked bikeshare saw the most success when local governments created an environment conducive to a systems approach by supporting operators through introducing infrastructure like dedicated travel lanes, attentively enforcing regulations, and providing leading shares of direct investment or forms of subsidy (Zhang et al., 2015). Free-floating systems built on these successes while disrupting provision. This new form from private operators grew dramatically in a short time, from a total fleet of 2 million in 2016–23 million the following year, and by 2018 could be found in 200 cities, claiming 1 out of 6.5 people in China as a registered user of some system (Gu, Kim, & Currie, 2019). As before, the systems have worked best alongside correlated transport infrastructure, and have been effective as last-mile solutions (Zhao et al., 2018). Short-distance motor vehicle trips have dropped since the introduction of free-floating systems and the transport mode share of cycling has increased (Gu et al., 2019). This short period has seen a regulatory arc that will look familiar to observers of the North American systems that followed. Initially, free-floating bikeshare operators took advantage of little regulation from local or central government to flood cities with fleets, taking a supply-driven stance that competed for users above actual demand or established available parking space (and preferring the introduction of a new bike over more costly maintenance of existing units) (Gu et al., 2019). The central government took a neutral stance, leaving local governments to optimise regulatory definition of the state-operator-user relationship; local governments responded over the course of 2017 by introducing gradually stricter regulations that made operators responsible for parking and congestion, increased enforcement, and in some cases implemented geofencing and fleet capacity caps (Gu et al., 2019). Local governments now have a similar level of involvement and guidance of free-floating systems as they did with their docked prede- cessors (Gu et al., 2019). TRANSPORT REVIEWS 709

Nomenclature and mechanics of non-station-based bikeshare Nomenclature There is debate surrounding the naming of bikeshare systems that do not use docking stations. As Paul DeMaio points out (DeMaio, 2018b), the term “dockless” is problematic due to its transitional, temporary nature. As such, we use “free-ﬂoating” to describe these systems.

Mechanics Free-floating bikeshare uses GPS-located bikes with on-board locks and mobile apps (Figure 1) that can locate bikes and electronically unlock them. At the end of a trip, users lock a bike in place with the on-board lock, which can be wheel-based, U-lock style, or cable style (Figure 2). These locks typically do not require attaching the bicycle to an external object (except when required by regulation). Some “hybrid” systems allow riders to pick up or drop off bikes at either a station or a non-station location. The ability to lock in place enhances trip chaining by allowing a user to lock at intermediate destinations between origins and final destinations. “Geofencing” with GPS can corral bikes within a certain boundary area or keep them out of others by preventing rides from finishing outside of designated zones.

Figure 1. Screenshot examples of free-ﬂoating bikeshare apps for locating, unlocking, and locking bikes. Bike locations indicated by icons (green limes in 1a and orange pins in 1b). Maps centre around users current location (indicated by blue dot in 1a) and show battery life using battery symbols (when there are e-bike options, e.g. 1a). When a user gets to a bike, they would press a scan button (bottom, both images) to activate that bike and begin a trip. 710 J. A. HIRSCH ET AL.

Figure 2. Examples of diﬀerent mechanisms for locking free-ﬂoating bikeshare bikes (illustrated with grey arrow). Wheel style locks present on companies such as Lime or Spin Bikes (a), u-lock style locks present on companies like Social Bikes operating Relay Bikes (b), and cable style locks on Pace bikes (c). Permissions obtained for all photos credited in image.

Variability within bikeshare fleets Since bikes do not need to conform to fit a dock, free-floating systems can have a variety of bicycle options. For example, the company U-bicycle offers four types of bikes in their fleet: two cruisers with relaxed riding positions, a road bicycle with touring handlebars, and an electronically assisted (“e-bike”) that can travel at speeds of up to 20 MPH (32 KPH). Lime- Bike includes types of manual bikes (1-speed, 3-speed, 8-speed), as well as e-bikes, and electronically assisted scooters. Other systems, like JUMP or Riide bikes, are exclusively comprised of e-bikes.

Business and governance models Business model Previous generations of station-based bikeshare have used at least five different business models (Shaheen et al., 2010). While select free-floating systems have formal partnerships between municipalities or non-profit institutions (Camden, NJ, New York, NY, and Reno, NV), nearly all free-floating systems operate as commercial “for-profit” companies, providing bikesharing services that depend on usage fees. However, there are two important dis- tinctions between previous for-profit station-based systems and these for-profit free- floating systems. First, many free-floating systems operate in cities that explicitly restrict third-party advertising on the bikes (e.g. Los Angeles, CA (City of Los Angeles, 2018)). Second, more notably, most of these companies have raised millions of dollars of venture capital (Tchebotarev, 2017). Some operators require users to create an account and pay a deposit, to be refunded if the user unsubscribes. In practice, recent reports indicate China-based deposits being used for inappropriate practices and users losing deposits when companies go bankrupt (Dai, 2017). At present this has not happened in North America. Companies often charge by the ride (e.g. Ofo is $1/ride; JUMP is $2/ride) with different limits by city (e.g. 30 or 60 TRANSPORT REVIEWS 711 min). If riders go over the allotted time, they are charged for overages. Some companies have monthly or annual passes that include a set amount of daily ride time, while others have “frequent rider” prices where users can purchase trips in bulk (e.g. LimeBike charges $30 for 100 rides). Many companies aim to stimulate growth of users by offering free ride promotions in new markets.

Governance models Governance models for free-floating bikeshare are currently evolving. Whereas public- private partnerships for station-based systems have required close coordination among multiple stakeholders, free-floating share operators have often been private companies intent on deploying rapidly and interacting with cities through permits and operating legislation. In the case of free-floating bikeshare, many cities are limited when trying to recover the (often unknown) costs of regulation. This can confine city revenues and reduce municipalities’ control over infrastructure service levels. As of 2018, some cities had begun to put ordinances in place to constrain free-floating bikeshare, regulating companies to control market failures while preserving the positive effects of bikeshares by integrating them into urban mobility system building efforts led by the city (Yanocha, 2018). To date, most are pilots that were instituted on a trial basis. Ordinances set forth permit fees, per-bike fees, and other financial requirements such as relocation fees, insurance levels (typically $500,000 to $1 million), and performance bonds (Table 1). Ordinances frequently outline safety and maintenance requirements, and customer service expectations. Some detail fleet size, a specific operating area, and establish response times to which companies must adhere when moving bikes back to the service area. Many ordinances include efforts to address themes identified below. These include operating outside existing station-based service areas, minimum rides for bikes to discourage oversaturation, parking limitations (e.g. location, length of time), data sharing, and equity (e.g. bicycle distribution and access). In July 2018, NACTO published guidelines for regulation and management of these systems that prioritises and legitimises cities’ roles in governance of these new technologies (National Association of City Transportaion Officials (NACTO), 2018b). These guidelines included regulations for all cities (oversight, data standards, and small vehicle standards) and areas to be evaluated locally (parking, community engagement, and equity). As the industry is expected to rapidly change, NACTO plans biannual updates of the guidelines. Of note, some free-floating operators have pursued state-level legislation that would preempt local regulations. Pre-emption bills were introduced and failed in spring 2018 in Florida and Oklahoma (Bossert, 2018a, 2018b).

Current free-floating bikeshare in North America Free-floating bikeshare has experienced a rapid expansion across North America. Accord- ing to the National Association of City Transportation Officials (NACTO), during the second half of 2017 free-floating bikeshare companies introduced around 44,000 bikes within the US, accounting for 44% of all share bikes (National Association of City Transportation Officials (NACTO), 2018a). Yet free-floating bikes represent a substantially smaller proportion of bikeshare trips – only 4% in 2017 (National Association of City Transportation 712 Table 1. Select governance components from cities with notable regulations and/or numerous operators updated June 28, 2019. Damaged/ Stagnant

Fleet size Equity Programming or Vehicle Permit Fee/ Performance AL. ET HIRSCH A. J. City, State Type bounds Requirements Provision Application Fee Per Bike Fee Bond Permit Length Status Austin, TX License 500 per . Non-smartphone X $0/$0 $30 $100/bike 6 months Open company option . Outreach or marketing to underserved neighbourhoods required . Minimum of 2 trips/ bike/day . Bonus of 250 units to serve areas outside core

Charlotte, NC Permit 200–500 (50 – . Data sharing X $0/$0 $0 $0 Permits end July 31, Open, replaced by dynamic 2019 scooter maximum for regulations scooters) Chicago, IL Pilot ≤350 . Limited to South X $250/$0 $50 $0 Pilot ended Nov 1, Open, replaced by Side 2018; seemingly scooter pilot . Spatial replaced with requirements scooter pilot from (during June 15 to October rebalancing) 15, 2019 . Cash payment (Greenﬁeld, 2019) option . Employment and hiring plan . Outreach or marketing to underserved neighbourhoods required . One community event

Dallas, TX Permit — X $21 $10,000 6-months Open . Quarterly data $808 ($404 reports renewal)

Durham, NC Permit 1,200 . Reducing barriers to X $0/$1000 $50 (pedalecs)/ $10,000 Annual Open, revised access as part of $25 (manual)/ October 2018 permit application $100 (scooter) . Spatial requirements (during rebalancing) . Non-smartphone option . Cash payment option

Los Angeles, Permit 500–3,000 . Spatial bonus (2,500 X $20,000/$0 $130 ($39 in $80/vehicle Annual Open, launched CA extra in disadvantaged December 2018 “disadvantaged areas) communities,” 5,000 in San Fernando Valley) . Non-smartphone option . Cash payment option . Low-income plan (waives deposit) . Mandatory community engagement plan RNPR REVIEWS TRANSPORT

Philadelphia, Pilot 1,200 . “Lock-to” — $76,000/$2,580 ——Annual Open, PA technology applications required accepted . Data sharing August 2019 . Usage zones determined by City

(Continued) 713 Table 1. Continued. 714 Damaged/ Stagnant Fleet size Equity Programming or Vehicle Permit Fee/ Performance City, State Type bounds Requirements Provision Application Fee Per Bike Fee Bond Permit Length Status AL. ET HIRSCH A. J. . Provision for unbanked/non- smartphone users

Phoenix, AZ Permit 500 per . “Lock-to” — $500 $20 — 6 months Discontinued May company technology 2019 (Boehm, required 2019)

San Diego, CA Permit Negotiated case . $15/unit fee — $5,141 $150 — 6 months Eﬀective July by case reduction for 2019 oﬀering equity plan

San Francisco, Permit 12,000 for all . Spatial requirement X $35,288/$4,947 $4–20 $25,000 18 months Opened January CA ﬂeets . Cash payment (dependent on “endowment” 2018 applying combined option total number) payable only to JUMP, . Low-income plan $2,500/year renewed May (waives deposit) 2019 . Requirement of strategy to have 1 low-income member for every 5 bikes approved . Outreach or marketing to underserved neighbourhoods required . Multilingual website, call centre, and app interface required

Seattle, WA Permit 5,000 (min. of . Spatial requirement X $146/$209 per $50 ($250,000 $10,000 surety Annual Open, updated 80% of max (at least 10% of hour of review max.) bond August 2018 fleet size) fleet in Equity Focus Areas) . Size bonuses for adaptive fleet . Fleets of over 2,500 must serve entire city . Reduced fare programme for pedalecs . Requirement of one low-income barrier reduction

Washington, Pilot 600 per type, X $250/$50, $100 $5/vehicle/ $10,000 Annual Open, updated DC increase of per subsequent month May 2019 25% per year, plus one- quarter at time $25 DDOT “technology discretion fee” Table adapted from NACTO Guidelines for the Regulation and Management of Shared Active Transportation (V1) (National Association of City Transportaion Oﬃcials (NACTO), 2018b), manually updated June 2019 using available regulations (City of Austin, 2019; City of Charlotte, 2018, 2019; City of Durham, 2018a, 2018b; City of Los Angeles, 2019; City of Philadelphia, 2019; City of San Diego, 2019; City of San Francisco, 2019; City of Seattle, 2018c; District of Columbia, 2019). Data include regulations on university systems, some of which may not be accessible to the public. Abbreviations: AZ (Arizona); CA (California); DC (District of Columbia); IL (Illinois); NC (North Carolina); TX (Texas); WA (Washington). RNPR REVIEWS TRANSPORT 715 716 J. A. HIRSCH ET AL.

Officials (NACTO), 2018a), a consequence in part of many systems’ only partial implementation throughout the majority of the year. In 2018, that percentage grew to ∼20%, although that year also saw the beginning of a precipitous drop in free-floating bikeshare systems as companies left the market or retooled for electric scooter use (National Associ- ation of City Transportaion Officials (NACTO), 2019).

Existing companies and cities By 2017, NACTO identified five larger free-floating bikeshare companies operating within the US – JUMP (formerly of Social Bicycles, now owned by Uber, (Dickey, 2018)), Limebike, MoBike, Ofo, and Spin. Smaller companies include Donkey Republic, Pace (formerly Zagster), Riide, and VBike. Two additional companies exist only in Canada – Dropbike and U-bicycle. A sixth major company, BlueGoGo, launched and declared bankruptcy within 2017. As of July 19, 2018, we catalogued 213 free-floating bikeshare systems across 159 cities in 39 US states and 5 Canadian provinces; by June 28, 2019 we catalogued 233 systems across the US, Canada, and Mexico (Table 2). Fully free-floating systems were more common, with more locations identified compared to hybrid systems. In 2018, only two companies identified had exclusively e-bike fleets (JUMP and Riide) with several offering both manual and e-bikes. By 2019, new e-bike only companies opened and others had shifted exclusively to e-bike or scooters. In all, operators had programmes in a minimum of 1 location and maximum of 63 (Lime) per operator. Several larger cities had multiple systems, including: Austin, TX; Charlotte, NC; Chicago, IL; Dallas, TX; Durham, NC; Los Angeles, CA; Phoenix, AZ; San Diego, CA; San Francisco, CA; Seattle, WA; and Washington, DC. Determining whether companies served entire cities, or select neighbourhoods within cities such as university campuses, was challenging. For example, in 2018, Spin serves 31 campus locations, several of which overlap with Spin cities (e.g. Duke University in Durham, NC). Spin also provided service to multiple campuses within a single city (e.g. Goucher College and Towson University in Towson, MD). These lists are dynamic for three key reasons. First, low implementation costs compared to station-based bikeshare mean that new services launch frequently. Second, this quick expansion has left some companies overextended and in need of scaling back. For example, in late-July 2018, Ofo announced it would cease operations in almost all US markets (Brown, 2018; Feng, 2018; Salazar, 2018). Third, at least two existing station- based companies (Motivate and B-Cycle) are working on hybrid or free-floating products to complement existing systems and compete with new companies.

Research and practice topics relevant to free-floating bikeshare Important differences between station-based and free-floating bikeshare raise novel questions within a North American context. We identify future directions for research and practice from synthesis of the literature, key informants, and experiences during the first year of operation in North America. These fall into five broad themes (Table 3).

Usage Bikeshare usage may be for mobility (place to place transport) as well as for physical activity. Given new components of free-floating bikeshare (leaving bikes in any location, Table 2. Summary table of free-floating and hybrid bikeshare systems in North America As of July 19, 2018– updated June 28, 2019. Fleet Type States or Provinces (# Reported Cities) (strike-through indicates Total Reported Change Type of System Companies Manual E-bike closed between July 19, 2018 and June 28, 2019) Cities 2018-19 Free-floating (“dockless” or Ant X MA (7) 7Exp. “flexible”) CycleHop/HOPR X CA (1); FL (2); IL (1) 4 Exp. Dezba X CDMX (1) 1 New Donkey Republic X OH (1); TX (1) 2 1 Contr. Dropbike X X BC (2); KS (1); MB (1); ON (5); QC (1) 10 Exp. Gotcha X AL (1); FL (1); GA (3) (4); IL (1); KY (1); LA (1); MD (1); MS (1); NC (3) (4); 25 26 Exp. NY (3); OH (1); OK (2); SC (2); VA (1); VT (1); WA (1); WV (1) JUMP X AZ (2); CA (6); CO (1); DC (1); GA (1); IL (1); NY (1); RI (1); TX (2); WA (1) 17 16 Exp. LimeBike (now X X AZ (1); CA (17); CO (2); DC (1); FL (2); HI (1); IL (2); IN (2); MA (15); MD (1); MO (1); 63 Conv. to Lime) NC (3); NJ (2); NV (1); NY (3); OH (3); TX (4); WA (2) scooters Mobike X CA (1); DC (1); NC (1); TX (2); CDMX (1); 5 1 Contr. Ofo X AZ (1); CA (2); CO (1); DC (1); FL (1); MA (2); NC (2); TN (1); TX (2); WA (1) 14 0 Clos. Riide X DC (1); NY (1); SK (1); VA (7) 10 Private leases Spin X X AR (1); AZ (2); CA (7); CO (1); CT (1); DC (1); FL (1); IN (1); KS (1); 46 0 Conv. to KY (1); MD (4); MI (1); MS (1); NC (3); NY (1); OR (1); PA (1); SC (1); scooters TX (10); UT (3); WA (2); WI (1) U-bicycle X X BC (1) (2) 1 2 Stasis V-bikes X X NC (1); TX (1) 2 1 Stasis VBike X CDMX (1); SI (1); VE (1) 3 Exp. Veoride X X AL (2); AR (3); CA (2); IA (2); IN (1); IL (2); KS (3); KY (1); MA (4); 27 Exp. NH (2); OH (1); TX (4) Wheels X CA (2); GA (1) 3 Exp. Hybrid (can be parked at stations B-Cycle Dash X X CO (1); OK (2); TN (1); TX (1); WY (1) 6 Conv. to Hybrid fl or free- oating) Nextbike X X BC (1); FL (1); NJ (1); OH (1) 4 Exp. REVIEWS TRANSPORT Pace X AL (1); CA (1); CO (1); FL (1); IL (1); IN (2); MD (1); NM (1); NY (2); 15 14 Stasis TN (1); TX (1); VA (2) (1) Social Bicycles X AK (1); AL (1); AZ (1); CA (3); FL (5) (4); GA (1); ID (2) (1); IL (1); KS (1); KY (1); 40 29 Contr. LA (1); MS (1); NC (4); NY (5); OH (1); OK (1); ON (2); OR (2); SC (2); VA (1); VT (1); WA (1) Exp.=expanding; Contr.=contracting; New=new company; Clos.=closed; Conv.=conversion. Abbreviations: AK (Alaska); AL (Alabama); AR (Arkansas); AZ (Arizona); BC (British Columbia); CA (California); CDMX (Mexico City, MX); CO (Colorado); CT (Connecticut); DC (District of Columbia); FL (Florida); GA (Georgia); H (Hawaii); ID (Idaho); IL (Illinois); IN (Indiana); KS (Kansas); KY (Kentucky); LA (Louisiana); MA (Massachusetts); MB (Manitoba); MD (Maryland); MI (Michigan); MO (Missouri); MS (Mississippi); NC (North Carolina); NJ (New Jersey); NM (New Mexico); NY (New York); NV (Nevada); OH (Ohio); OK (Oklahoma); ON (Ontario); OR (Oregon); PA (Pennsylvania); QC (Quebec); SC (South Carolina); SI (Sinaloa, MX); SK (Saskatchewan); TN (Tennessee); TX (Texas); UT (Utah); VA (Virginia); VE (Veracruz, MX); VT (Vermont); WA (Washington); WI (Wisconsin). 717 Updated June 28, 2019. Data include university systems, some of which may not be accessible to the public. Data from: Smart Cities Dive, available at: https://maphub.net/smartcitiesdive/Mobility- map/download/csv; The Bike Sharing World Map by Russell Meddin and Paul DeMaio, available at: https://www.google.com/maps/d/u/0/viewer?mid=1UxYw9YrwT_R3SGsktJU3D-2GpMU; and the Global Bike Share Map, by Oliver O’Brien, available at: https://bikesharp.com/#/3/-60/25/. 718 J. A. HIRSCH ET AL.

Table 3. Future directions for research and practice in free-floating bikeshare Theme Topics or Questions Usage Mobility . How does free-floating bikeshare play into mobility, and does this role differs from station-based bikeshare? . Does uniformity of company across cities encourage bicycle use among tourists? . How does a single user differ in travel behavior when using the same free-floating bikeshare system across many cities?

Physical Activity . What proportion of the population use free-ﬂoating bikeshare? . What are the trip details of users, including mode substitution, trip frequency, duration, and generation of new trips? . Does population physical activity increase after introduction of free-ﬂoating bikeshare? If so, how much?

Equity Spatial Equity . Is spatial access to free-floating bikes distributed equitably across population groups? . What is a suitable sized programme to achieve spatial equity across a city, while still being profitable? . What types of governance result in more equitable free-floating bikeshare systems? . What is a suitable model for optimising equity during free-floating bikeshare rebalancing? . What user-based strategies might be effective for rebalancing within a free-floating bikeshare system?

Social Equity . What are the demographics of users within free-floating systems? . What are the barriers and facilitators to using free-floating systems? . What pricing structures and outreach initiatives are effective in reaching low-income residents? . What types of bikes in free-floating systems encourage use of bikeshare, and for whom?

Sharing Resources Existing Systems . How do we design legislation or fare integration between non-station-based systems with station-based systems? . How often are free-ﬂoating bikeshare systems adhering to their service areas? How often do they come in conﬂict with other systems? . How does user experience vary according to number and type of systems? . What are some models of multimodal systems that integrate across bikeshare, carshare, transit, and more?

Bike Storage . What is the frequency, impact of, and responsibility for right-of-way issues? . Do technical and infrastructural ﬁxes such as geofencing and dedicated parking areas resolve parking concerns? . How do storage concerns evolve as free-ﬂoating systems proliferate? . What is the prevalence of vandalism and what physical, social, environmental, or regulatory characteristics discourage vandalism?

For-Profit Model Data and Privacy . What models of data sharing between cities and bikeshare companies provide public benefits without compromising commercial interests or user interests? . How do we create comprehensive standards, definitions, and mechanisms to ensure data quality and comparability?

Financial Sustainability . What ride rate would free-floating bikeshare bikes need to reach to be profitable? . What are effective business or public-private partnership models to replace venture capital dependency? . What are other potential sources of revenue for free-floating bikeshare?

Context Helmet Laws . What are strategies to offer helmets to free-floating bikeshare riders? Does compliance differ by strategy? . Does offering helmets for free-floating bikeshare encourage use (and compliance with the helmet law)

(Continued) TRANSPORT REVIEWS 719

Table 3. Continued. Theme Topics or Questions . How can we streamline local laws to reduce user confusion for inconsistencies of helmet requirements within single free-ﬂoating ﬂeets?

Physical and Social . How do differences between North American and Chinese contexts play out in Environment introduction, implementation, and success of free-floating systems? . Does free-floating bikeshare create opportunities or obstacles to new infrastructure? . How does the social environment shape success of free-floating bikeshare systems and vice versa? . What environmental features may be needed for free-floating bikeshare to be successful? . How does city geography impact potential success of free-floating bikeshare systems? . In what ways can be learn from success on university campuses to create favourable biking conditions in larger, non-university cities? . How might bikeshare success from university campuses translate into additional biking among graduates of these universities as they move to other cities?

starting trips from dispersed locations), the systems may be used differently than station- based bikeshare, with differential influence on both types of usage.

Mobility By offering alternatives to congested streets, bikeshare holds potential to reduce travel times (Faghih-Imani, Anowar, Miller, & Eluru, 2017; Jäppinen, Toivonen, & Salonen, 2013). This benefit is potentially more pronounced in free-floating systems that can take riders directly from their start point to destination. Station-based bikeshare is disproportio- nately used for shorter trips as compared with private bikes (López-Valpuesta & Sánchez- Braza, 2016). Preliminary analyses of free-floating bikeshare usage in China suggests riders ride similarly short rides in both system types (Chen, Wang, Sun, Waygood, & Yang, 2018), but North American riders may make longer trips in a free-floating system when not bounded by station locations. Policies may also affect distances: a per-minute pricing structure could discourage longer trips; though analysing operator data for trips per bike, per day, would clarify system performance. Finally, tourists familiar and registered with a free-floating system operated by the same company as in their hometown could be more likely to use it elsewhere. If data on users across different cities serviced by the same operator became available, there would be new avenues of inquiry for bikeshare use across contexts. Future inquiries should aim to: 1) understand how free-floating bikeshare contributes to mobility, and whether this role differs from station-based bikeshare. Specifically, shifts in mode choice, travel times, trips per bike per day, and trip length remain unstudied in free-floating systems. Because companies operate across multiple cities, future work could leverage national data to: 2) understand differences in travel patterns for one user across many different cities, providing useful benchmarks for mobility system comparison over a range of unique urban contexts.

Physical activity While there is evidence to suggest that station-based bikeshare can increase bicycling (Fuller et al., 2013), previous research indicates that only a small proportion of residents use 720 J. A. HIRSCH ET AL. bikeshare, resulting in little impact on population-level physical activity. However, the larger service areas and sheer number of locations with free-floating bicycle programmes suggest these systems may gain larger user bases than station-based systems. This may result in greater impacts on population physical activity, particularly if free-floating systems encourage those who currently do not cycle to begin riding. Still, concerns remain that replacing walking trips with bike trips can create a net reduction in physical activity. Key inquiries for determining population physical activity impact include the: 1) proportion of the population who use free-floating bikeshare; 2) trip details of users, including information about mode substitution, trip frequency and duration, and generation of new trips; 3) pre–post evaluations of the impact of dockless programmes on population cycling and physical activity levels; and 4) physical activity gained or lost from free-floating bikeshare use.

Equity Equitable access is a key consideration for bikeshare systems. Spatial equity (i.e. where bikes are available) and social equity (i.e. to whom bikes are available) of free-ﬂoating systems may diﬀer from that of station-based systems.

Spatial equity Research on station-based systems has found spatial inequality in station locations (McNeil, Broach, & Dill, 2018). In evaluations of seven US and five Canadian cities, neighbourhoods with higher socioeconomic status had better access to stations (Hosford & Winters, 2018; Smith, Oh, & Lei, 2015; Ursaki & Aultman-Hall, 2016). In free-floating systems, spatial equity is no longer dictated by station location. Without stations anchor- ing bikes to lower socioeconomic status neighbourhoods, bikes may end up in the neighbourhoods that reflect the higher socioeconomic status profile of bikeshare users. Conversely, free-floating systems may provide more equitable access simply because they distribute more bikes compared to station-based programmes. For example, one year into Seattle’s pilot, there were 10,000 bikes (City of Seattle, 2018b), twenty times the number available in their prior station-based programme, and comparable to New York’s Citi Bike, in operation five years and serving a much larger population. As a result, no neighbourhood was not served by bikes during the pilot (Mooney et al., 2019). Some cities have included equity targets in governance arrangements (Table 1). For example, Durham, NC requires operators to “maintain a sufficient number” of bikes “within census tracts of low median income” (City of Durham, 2017). Austin, TX offers a 250-unit bonus to operators who commit to a service area of at least five square miles outside the Downtown Austin Project Coordination Zone (City of Austin, 2018). Chicago requires operators to maintain at least 15% of their fleet in each quadrant of its service area on the South Side (City of Chicago, 2018). Aside from service boundaries, rebalancing remains the main mechanism for companies and cities to influence spatial equity. In general, there are two strategy types: operator-based strategies and user-based strategies (de Chardon, Caruso, & Thomas, 2016). User-based strategies usually include incentives encouraging riders to drop bikes in high-need locations, such as Philadelphia Indego bikeshare’s “IndeHero” programme where users can earn pass extensions by taking bikes from full locations or placing TRANSPORT REVIEWS 721 bikes in empty stations. To date, these incentives have not been sufficient to adequately rebalance bikes, necessitating operator-based strategies (wherein the operator restores bikes to locations where more rides begin) as a complement. There is robust literature on operator-based rebalancing (Cruz, Subramanian, Bruck, & Iori, 2017; Zhang, Yu, Desai, Lau, & Srivathsan, 2017; de Chardon et al., 2016; Dell’Amico, Hadjicostantinou, Iori, & Novel- lani, 2014; Ho & Szeto, 2017), but as of July 2018 only two papers had examined rebalancing models for free-floating bikeshare (Pal & Zhang, 2017; Xu, Ji, & Liu, 2018). Free-floating systems are challenging combinatorial optimisation problems, because any bicycle can be rebalanced to (almost) any location within a service area. These initial investigations of free-floating rebalancing focus primarily on demand. Areas for future equity research include: 1) whether free-floating bikes are distributed equitably among neighbourhoods of differing demographics; 2) suitable programme size to achieve spatial equity while still being profitable; and 3) types of free-floating bikeshare governance that are effective for encouraging equity. Critical rebalancing gaps include identifying: 4) suitable models for optimising free-floating bikeshare rebalancing; and 5) effective user-based strategies for rebalancing within free-floating systems (e.g. incentives in geofenced areas).

Social equity Across North American cities, station-based programme members tend to be male, non- Hispanic White, employed, and have higher educations and incomes as compared to the general population (Fishman, 2016; Ricci, 2015; Shaheen, Cohen, & Martin, 2013). These trends may reflect demographic patterning of established barriers to bikeshare system use, such as cost and pricing structure, lack of awareness about how to use bikeshare, and limited access to credit cards or smartphones, which are often required for registration (McNeil et al., 2018). Most of these barriers are present in free-floating systems as well, with one study in China similarly finding users to be younger, better-educated, and have higher incomes (Xin, Chen, Wang, & Chen, 2018). Some free-floating systems offer highly discounted rates to less pri- vileged populations (e.g. LimeBike offers 100 rides for $5 for low-income users). Moreover, diversity in free-floating system fleets (e.g. e-bikes) may accommodate populations of varied ages and abilities. Some cities have mandated social equity initiatives (Table 1), including cash payment options for the “unbanked.” Similarly, free-floating systems increasingly offer non-smartphone options (Soper, 2017), though alternate options typically still require text messages to unlock bikes. Some other equity initiatives include community engagement, hiring requirements, or provision of multilingual services. Areas for research on social equity of free-floating systems include identifying: 1) demographic characteristics of free-floating system users; 2) barriers and facilitators to using free-floating systems; 3) effective pricing structures and outreach initiatives to reach low-income residents; and 4) how fleet diversity can encourage use among different populations.

Sharing resources Because free-floating bikes can be left anywhere, the launch of these systems have resulted in conflicts regarding shared amenities. These conflicts arise both with respect 722 J. A. HIRSCH ET AL. to station-based systems in adjacent or overlapping service areas, and also with private citizens encountering bikes left on pedestrian routes, bicycle lanes, or car parking spaces. Moreover, free-floating bikes exacerbate vandalism and security concerns common to station-based systems.

Coexistence with existing systems Many station-based systems (e.g. New York’s Citi Bike and other Motivate systems) have exclusive operating contracts. However, free-floating operators may launch in adjacent areas, resulting in inevitable “leakage” when free-floating bikes are parked in station- based system service areas, provoking regulatory conflicts. In Boston, bikes from Ant were impounded by the city when they were found within station-based Blue Bike’s service area (Vaccaro, 2018). To prevent such situations, free-floating operators charge “out of system” fees when bikes are parked outside the service area. Free-floating bikeshare’s engagement with existing transportation systems holds potential to shift the travel landscape. Free-floating systems appear to play a role in first- and last-mile transit access. For example, in Seattle, 74% of people surveyed had used bikeshare to access transit. Anticipating synergies, the car-sharing company Uber recently purchased JUMP, and has integrated bikeshare with its peer-to-peer automobile ridesourcing service in a smartphone app (Lekach, 2018). Conversely, the bikeshare company Mobike has considered adding cars (O’Keefe, 2018) and Lime has begun a limited carshare pilot, LimePod, in Seattle (Gartenberg, 2018). Like the trend of incorpor- ating electric scooters, this complicates the increasingly dynamic urban mobility system landscape. Integrating different systems is promising for free-floating bikeshare success, but remains under-researched. Gaps include: 1) designing legislation or fare integration between free-floating systems with station-based systems; 2) evaluation of service area adherence; 3) understanding user experience with multiple systems; and 4) exploration of multimodal systems that integrate across bikeshare, carshare, ridesourcing, transit, and other modes.

Bike storage One major public, governance, and operational concern with free-floating bikeshare has been ensuring bikes are stored appropriately (City of Seattle, 2018a; Dickinson, 2018). Donald Shoup notes that any mode of transport is comprised of a vehicle type, right of way usage, and terminal capacity (storage) (Shoup, 2017): between docked and free- floating bikeshare modes, the only difference is with terminal capacity which can often happen in the right of way. Whereas returning bikes to docking stations in station- based systems leaves the system in a predictably tidy state, free-floating bikes can be left in inconvenient places or be moved without being unlocked, including in ways that destroy the bike. Broadly, there are three categories of concern with bicycle storage. First, bikes are frequently left blocking sidewalk or roadway right-of-ways. While some enabling legislation specifies financial penalties to operators for improperly parked bikes, legislation is hard to enforce, especially outside neighbourhoods overseen by business improvement districts. Operators have tried techniques including “gamification” of proper parking to encourage riders to park bikes respectfully, with only modest results. Hybrid systems often incentivize returning bikes to stations; Relay bikeshare (Social TRANSPORT REVIEWS 723

Bikes, Atlanta, GA) charges riders $2 to leave a bicycle outside a station and gives $1 credits for returning “out-of-hub” bikes to stations. One emerging idea is dedicated or “geofenced” preferred parking areas (Bhuiyan, 2017;Mah,2018). These could be indicated within app interfaces and combined with gamification schemes rewarding proper parking. Second, issues arise in the combination of right of way usage, and terminal capacity (storage) (Shoup, 2017). Because operating companies are privately held, some citizens object to right-of-way being ceded for free (Harris, 2018). Free or very low cost curbside car parking is a longstanding norm in North American (Shoup, 2017). However, a sudden appearance of numerous share bikes on the sidewalk, as well as visual chaos of sizeable groups of bright, sometimes overturned, bikes may exacerbate the sense of injus- tice in this area. Finally, the ability to anonymously move bikes has led to high-profile vandalism acts, which receive extensive press and social media coverage (Miller, 2018; Young, 2018). For example, there was a massive pile of bikes in Dallas shortly after programme rollout. Generally, bikes have ended up in rivers (Heffernan, 2018), up trees (Rose, 2017), and even in modern-art sculptures (Brown, 2017). Often vandalism is followed by statements bemoaning tragedy of the commons problems (Hardin, 1968), or narratives of hate and anger toward bikeshare and bikes overall. Key research gaps for free-floating bicycle storage include ascertaining: 1) frequency, impact of, and responsibility for right-of-way issues; 2) effectiveness of technical and infrastructural strategies such as geofencing and dedicated parking; 3) evolution of storage concerns as free-floating systems proliferate; and 4) prevalence of vandalism and what physical, social, environmental, or regulatory characteristics discourage vandalism.

For-profit model The for-profit model of free-floating systems complicates data sharing logistics and raises concerns about financial sustainability and longevity of these systems.

Data and privacy Station-based bikeshare collaborations with public transport agencies or local governments have facilitated a relatively smooth flow of data to city planners. By contrast, most free-floating system operators do not have pre-established data sharing systems, resulting in a “black box” of who uses the bikes, where, and for what. Many operators claim that their trip data is proprietary. Nonetheless, data sharing requirements are becoming increasingly common in legislation, particularly in more proactively regulated systems such as Seattle, Austin, and Durham. Further, the ways that operators collect, store, and share data varies between systems and cities. In Washington, DC, data from Mobike, Spin, and JUMP are provided in General Bikeshare Feed Specification (GBFS), which allows integration with station-based system data. However, requiring GBFS is not pervasive across jurisdictions, and operators have raised concerns that competitors will see and use their data. Companies are also responsible for user privacy— a concern when sharing demographics or travel data. In response to these concerns, Austin adopted a mandatory “opt-in” clause for sharing user data. Some cities, such as Seattle, have chosen a model 724 J. A. HIRSCH ET AL. where all data is routed through a third-party to ensure user and company data rights are maintained. Key research areas for data and privacy include: 1) identifying which data cities need for planning, and how to share these data without compromising commercial or user interests; and 2) creating data standards, definitions, and mechanisms to ensure data quality and comparability, which will in turn contribute to more robust analyses.

Financial sustainability Previous research on station-based bikeshare demonstrated positive cost–benefit estimates, especially driven by time savings and increased spatial functioning of cities (Bullock, Brereton, & Bailey, 2017). Yet the economic impact of free-floating bikeshare, particularly the financial sustainability for operators, remains unknown. Many operators, backed by venture capital, took an aggressive approach to expansion, deploying thousands of bikes and offering substantial promotional discounts. Since ridership fees are a primary revenue source for operators, especially in locations restricting third party advertising, reports that ridership in many US markets is below what may be needed to break even (Brown, 2018) raises sustainability concerns. Several operators have filed for bankruptcy, merged with other companies, or ceased operations in all or some cities (Tchebo- tarev, 2017). Determining the following may help ascertain financial sustainability: 1) ridership rates, regulatory environmental, and population settings that make free-floating bikeshare profitable; 2) effective business or public-private partnership models to replace venture capital dependency; 3) other potential income streams (e.g. third-party advertising).

Context Context, including city regulations, environment, and size, is a prime determinant of free- ﬂoating bikeshare system success.

Helmet use There is concern that bikeshare riders wear helmets less frequently than private bicyclists (Basch et al., 2015; Fischer et al., 2012; Kraemer, Roﬀenbender, & Anderko, 2012; Mooney, Lee, & O’Connor, 2019), and controversy surrounds the raised risks of traumatic brain injury or death during collisions (Graves et al., 2014; Salomon, Kimbrough, & Bershteyn, 2014). However, it is possible that bikeshare introduction may reduce cycling risk of injury not only owing to safety-in-numbers phenomena (Elvik & Bjørnskau, 2017) but also because, in spite of not wearing helmets, bikeshare users appear to be less susceptible to severe injury than other cyclists (Fishman & Schepers, 2016). The causes of this lower risk are unclear; bikeshare riders may ride more slowly and safely than private bike riders (Fishman & Schepers, 2016). Several systems (e.g. Vancouver, BC’s Mobi) oﬀer helmets and liners at stations to accommodate all-ages helmet legislation (Kett, Rivara, Gomez, Kirk, & Yantsides, 2016). Despite complementary helmet provision, use remained lower than among private bicyclists (Zanotto & Winters, 2017). In other jurisdictions without all-ages helmet laws, bikeshare systems have relied on education, although with little success (Basch et al., 2015). TRANSPORT REVIEWS 725

There are significant logistical hurdles to providing helmets for free-floating systems. First, the lack of stations precludes station-based helmet provisions. Moreover, in some jurisdictions, helmet laws vary by vehicle. For example, Los Angeles, CA’s helmet law covers electric scooters but not bikes or e-bikes. At present, no US free-floating systems provides helmets whereas some Canadian free-floating systems do. Newer governance ordinances require companies to encourage helmet use, including providing screenshots illustrating how customers will be educated in mobile and web applications (City of Los Angeles, 2018). Work is needed to determine: 1) diverse strategies to provide helmets to free-floating bikeshare riders; and 2) whether helmet availability for free-floating bikeshare encourages use. Furthermore, local jurisdictions may want to 3) consider and reduce confusion caused by helmet law inconsistencies across fleets.

Physical and social environment The physical and social environment plays an important role in all bicycle use (Götschi, Garrard, & Giles-Corti, 2016; Brown, Moodie, & Carter, 2017; Willis, Manaugh, & El- Geneidy, 2015), including in uptake of free-floating bikeshare. Some context barriers (Buehler, 2012), such as lack of bicycle parking at work, are simplified by free-floating bikeshare; whereas others such as lack of showers at work, remain. Social acceptability of bicycling and the behaviour of different road users toward cyclists may impact the success of free-floating bikeshare programmes. As of July 2018, only one paper had examined determinants of free-floating bikeshare use, finding cycling environment and safety to be a top priority to encourage more bikeshare use in China (Xin et al., 2018). Some recent work illus- trates the importance of physical and social environments with additional determinants for harder-to-reach sub-populations (Hirsch, Stewart, Ziegler, Richter, & Mooney, 2019). Additional work should examine how differences between North American and Chinese contexts impact introduction, implementation, and success of free-floating systems. Because free-floating bikeshare requires no fixed infrastructure, it may scale more easily to small cities or universities— which require fewer bikes and less rebalancing. Many of the free-floating and hybrid systems in Table 2 are sited in university campuses or in college towns. Universities offer large populations of young, able-bodied adults who do not prior- itise owning cars (Garikapati, Pendyala, Morris, Mokhtarian, & McDonald, 2016). Addition- ally, in partnership with universities, bikeshare systems can offer reduced rates or an opt- out membership through student fees. Restricted and often expensive parking on campuses further encourages bikeshare use. Notably, when Ofo announced withdrawal from many US markets, they ceased operations in Austin, TX a medium sized city with a large university but retained operations nearby in College Station, TX, where service was limited to Texas A&M University’s campus (Salazar, 2018). As free-floating bikeshare spreads across cities of different environments and sizes, some important research and practice gaps are: 1) does free-floating bikeshare create opportunities or obstacles to new infrastructure; 2) how does the social environment shape success of free-floating systems; 3) what environmental features may be needed for free-floating bikeshare to be successful; 4) how does city geography impact success of free-floating bikeshare; 5) what learnings from successful university programmes can inform programmes in larger, non-university cities; and 6) how might the experience of 726 J. A. HIRSCH ET AL. bikeshare at university campuses translate into additional biking among graduates as they move to other cities?

Conclusion Existing systems and current governance Since the emergence of free-floating bikeshare systems in 2017, there have been dramatic and rapid changes in North American bikesharing. Conversion to systems operated by GPS and without docking stations signals a full transition to the fourth generation of bikesharing described previously (Shaheen et al., 2010). Within the brief time since this new generation has emerged in North America, over 200 systems throughout more than 150 cities have launched, making over 40,000 bicycles available for public use. In contrast with previous systems that may have been collaborations with city or public entities, free-floating systems operate almost exclusively using for-profit models with operating permits rather than site permits or fee for service contracts. Governance models for these new systems are currently in early formulation and can include permit or operating fees, fleet size caps, safety requirements, parking restrictions, data sharing, and equity obligations. Guidance surrounding regulation of these systems was recently published by NACTO to assist and direct cities interested in deploying free-floating bikeshare (National Association of City Transportaion Officials (NACTO), 2018b).

Opportunities for further research While existing bikesharing evidence may translate to free-floating systems, additional domains and topics emerge as important. This overview included timely, relevant inquiries within each of these domains (Table 3). Many new issues arise from the ubiquity, fluidity, and business or governance models of these systems. Understanding who is using these bikes, where they are using them, and how that use may differ from previous systems is key to contextualising their role in current transport systems. Equity related to spatial location, user characteristics, or rebalancing may take cues from station-based systems, but also present novel obstacles related to technology and operations. Initial conflicts have originated from sharing space with existing systems, sidewalks and right of ways with pedestrians or the community, and unprotected bikes. The for-profit model has introduced obstacles for data sharing and concerns over financial sustainability. Finally, ease of deploying these systems means additional context factors, including helmet laws, environments and city scale, may play into the success or failure of new free-floating systems. Free-floating bikeshare systems hold promise for bringing bikes to many individuals across cities previously unable to sustain station-based bikeshare. However, despite a swift expansion across North America, systems have abundant obstacles to overcome for long-term sustainability. Some obstacles are a continuation of those from previous station-based systems: limited supportive infrastructure (e.g. bike lanes), theft or vandalism, and funding considerations (Shaheen et al., 2010). Other obstacles remain unique to these free-floating systems: sharing space (e.g. parking issues), equity from using technology that is not ubiquitous (e.g. requiring apps to access bikes), varied fleets with different types of vehicles (e.g. e-bikes, e-scooters), and governance models (e.g. how to TRANSPORT REVIEWS 727 share data with a for-profit company). Comprehensive research is needed on existing free- floating bikeshare pilots to gain insight into the potential of these systems in other contexts. Further, opportunities to examine free-floating bikeshare use across multiple cities are a novel avenue of inquiry formerly infeasible with city-based, station-based systems. As North American populations become more urbanised, cities’ complex mobility systems will need to continue to adapt. If the concerns outlined here can be overcome, free- floating bikeshare may provide unprecedented opportunities to bypass congested streets, encourage physical activity, and support urban sustainability.

Acknowledgements This project was funded by a research grant through the Better Bike Share Partnership a collabor- ation funded by the JPB Foundation to build equitable and replicable bike share systems. The part- ners include The City of Philadelphia, Bicycle Coalition of Greater Philadelphia, the National Association of City Transportation Oﬃcials and the PeopleForBikes Foundation. SJM was funded in part by the National Library of Medicine (Grant 1K99LM012868). MW is supported by a Michael Smith Foundation for Health Research Scholar Award (#16502). The Urban Health Collaborative and Dornsife School of Public Health supported this research through their investment in urban health research at Drexel University. The authors thank Maura Adams for her assistance gathering data and literature for this paper. The authors also acknowledge Joel Miller (Seattle Department of Transportation) and Alon Bassok (Washington State Transportation Center) for their expertise with the Seattle bikeshare pilot.

Disclosure statement No potential conﬂict of interest was reported by the authors.

Funding This work was supported by Michael Smith Foundation for Health Research: [Grant Number #16502]; Better Bike Share Partnership (People for Bikes): [Grant Number 2018 Research Grant]; U.S. National Library of Medicine: [Grant Number 1K99LM012868].

ORCID Jana A. Hirsch http://orcid.org/0000-0003-3355-5558 Joshua Stratton-Rayner http://orcid.org/0000-0003-2281-3718

References Basch, C. H., Ethan, D., Zybert, P., Afzaal, S., Spillane, M., & Basch, C. E. (2015). Public bike sharing in New York City: Helmet use behavior patterns at 25 Citi Bike™ stations. Journal of Community Health, 40(3), 530–533. doi:10.1007/s10900-014-9967-y Bhuiyan, J. (2017). Dockless bike-sharing startup LimeBike is working on creating virtual parking spots. Retrieved from Recode website https://www.recode.net/2017/12/24/16816352/dockless- bike-limebike-virtual-parking-spots-cities Boehm, J. (2019). Phoenix’s dockless bike program quietly dies, but e-scooters could arrive soon. Arizona Republic. Retrieved from https://www.azcentral.com/story/news/local/phoenix/2019/05/ 17/phoenix-kills-dockless-bike-share-program-make-way-e-scooters/3668729002/ 728 J. A. HIRSCH ET AL.

Bossert, H. (2018a). North American Bikeshare Association celebrates defeat of harmful Florida Bill - North American Bikeshare Association. Retrieved from https://nabsa.net/2018/03/23/north- american-bikeshare-association-celebrates-defeat-harmful-florida-bill/ Bossert, H. (2018b). North American Bikeshare Association triumphs over harmful Oklahoma Bill - North American Bikeshare Association. Retrieved from https://nabsa.net/2018/05/01/north- american-bikeshare-association-triumphs-harmful-oklahoma-bikeshare-bill/ Brown, E. (2018). China Bike-Sharing Giant Ofo to Shut Most U.S. Operations. The Wall Street Journal. Retrieved from https://www.wsj.com/articles/china-bike-sharing-giant-ofo-to-shut-most-u-s- operations-1531959910 Brown, S. L. (2017). A street sculpture made of dockless hire bicycles will be removed within days. The New Daily. Retrieved from https://thenewdaily.com.au/news/state/vic/2017/10/24/no-pot-gold- end-melbournes-obike-rainbow-sculpture/ Brown, V., Moodie, M., & Carter, R. (2017). Evidence for associations between traffic calming and safety and active transport or obesity: A scoping review. Journal of Transport & Health, 7,23–37. doi:10.1016/j.jth.2017.02.011 Buehler, R. (2012). Determinants of bicycle commuting in the Washington, DC region: The role of bicycle parking, cyclist showers, and free car parking at work. Transportation Research Part D: Transport and Environment, 17(7), 525–531. https://doi.org/10.1016/j.trd.2012.06.003. Bullock, C., Brereton, F., & Bailey, S. (2017). The economic contribution of public bike-share to the sustainability and efficient functioning of cities. Sustainable Cities and Society, 28,76–87. https://doi. org/10.1016/j.scs.2016.08.024. Chen, M., Wang, D., Sun, Y., Waygood, E. O. D., & Yang, W. (2018). A comparison of users’ characteristics between station-based bikesharing system and free-floating bikesharing system: Case study in Hangzhou, China. Transportation,1–16. https://doi.org/10.1007/s11116-018-9910-7. City of Austin. (2018). Director rules for deployment and operation of shared small vehicle mobility systems. Austin, TX. Retrieved from https://austintexas.gov/sites/default/files/files/Transportation/ Dockless_Final_Accepted_Searchable.pdf City of Austin. (2019). Dockless rules tracked changes. Retrieved from http://www.austintexas.gov/ sites/default/files/files/Transportation/Dockless_Rules_Tracked_Changes.pdf City of Charlotte. (2018). Dockless bike / E-scooter share permit requirements. Retrieved from https:// charlottenc.gov/Transportation/Programs/Documents/CharlotteDocklessBikeAndE- ScooterSharePermitRequirements.pdf City of Charlotte. (2019). 15-10010- Shared-Use mobility system permit requirements - Draft 1-9-19 (003). Retrieved from https://web.archive.org/web/20190126164140/https://charlottenc.gov/ Transportation/Programs/Documents/Shared-Use%20Mobility%20System%20Permit% 20Requirements.pdf City of Chicago. (2018). City of chicago permit requirements - for dockless bikeshare vendors only. Chicago, IL Retrieved from https://www.cityofchicago.org/content/dam/city/depts/cdot/bike/ general/Chicago_DoBi_Pilot_Program_Updated_06.29.18.pdf City of Durham. (2017). Ordinance to establish a permitting procedure to regulate the operation of bike share companies within Durham. Durham, NC Retrieved from https://durhamnc.gov/ DocumentCenter/View/17555/Bike-Share-Permit-Ordinance City of Durham. (2018a). Ordinance to regulate the operation of shared active transportation systems. Durham, NC Retrieved from https://durhamnc.gov/DocumentCenter/View/24271/Active- Transportation-Ordinance City of Durham. (2018b). Shared active transportation permit application. Durham, NC. Retrieved from https://durhamnc.gov/DocumentCenter/View/24724/Shared-Active-Transportation-Permit- Application City of Los Angeles. (2018). City of Los Angeles Mobility Data Specification. Retrieved from https:// github.com/CityOfLosAngeles/mobility-data-specification City of Los Angeles. (2019). LADOT dockless on-demand personal mobility one-year permit. Los Angeles, CA. Retrieved from http://basic.cityofla.acsitefactory.com/sites/g/files/wph266/f/Final20One- Year20Dockless%20Permit.pdf TRANSPORT REVIEWS 729

City of Philadelphia. (2019). 4.10 Philadelphia department of streets regulations governing a pilot program for dockless bicycle sharing. Philadelphia, PA. Retrieved from http://regulations.phila- records.com/pdfs/Department20of20Streets20Dockless20Bicycles%20Sharing.pdf City of San Diego. (2019). Mayor faulconer proposes new regulations for dockless scooters and bikes to improve public safety. Retrieved from https://www.sandiego.gov/mayor/news/releases/mayor- faulconer-proposes-new-regulations-dockless-scooters-and-bikes-improve-public City of San Francisco. (2019). SFMTA stationless bikeshare program permit application. San Francisco, CA. Retrieved from https://www.sfmta.com/sites/default/files/reports-and-documents/2019/05/ permit_application_final.pdf City of Seattle. (2018a). Free-Floating Bike Share - Transportation. Retrieved from http://www.seattle. gov/transportation/projects-and-programs/programs/bike-program/bike-share City of Seattle. (2018b). Free-floating bike share pilot evaluation report - Seattle department of transportation. Retrieved from https://www.seattlebikeblog.com/wp-content/uploads/2018/06/ Presentation.pdf City of Seattle. (2018c). Free-floating bike share program permit requirements for the 2018–2019 permit year (version 2.0). Seattle, WA. Retrieved from https://www.seattle.gov/Documents/Departments/ SDOT/BikeProgram/SeattleBikeSharePermitRequirements2018.pdf Cruz, F., Subramanian, A., Bruck, B. P., & Iori, M. (2017). A heuristic algorithm for a single vehicle static bike sharing rebalancing problem. Computers & Operations Research, 79,19–33. https://doi.org/10. 1016/j.cor.2016.09.025. Dai, S. J. M. (2017). As China’s no 3 bike sharer goes bust, riders worry about deposits. South China Morning Post. Retrieved from https://www.scmp.com/tech/start-ups/article/2120358/chinas-third- largest-bike-sharer-bankrupt-riders-worry-about-money de Chardon, C. M., Caruso, G., & Thomas, I. (2016). Bike-share rebalancing strategies, patterns, and purpose. Journal of Transport Geography, 55,22–39. https://doi.org/10.1016/j.jtrangeo.2016.07. 003. Dell’Amico, M., Hadjicostantinou, E., Iori, M., & Novellani, S. (2014). The bike sharing rebalancing problem: Mathematical formulations and benchmark instances. Omega, 45,7–19. https://doi. org/10.1016/j.omega.2013.12.001. DeMaio, P. (2018a). The bike-sharing world map - google my maps. Retrieved from https://www. google.com/maps/d/viewer?mid=1UxYw9YrwT_R3SGsktJU3D-2GpMU&hl=en DeMaio, P. (2018b, July 10, 2018). Please, don’t call it dockless. Retrieved from http://bike-sharing. blogspot.com/2018/07/please-dont-call-it-dockless.html Dickey, M. R. (2018). Social bicycles raises $10 million series a round, rebrands as JUMP bikes. Retrieved from TechCrunch website: http://social.techcrunch.com/2018/01/16/social-bicycles- raises-10-million-series-a-round-rebrands-as-jump-bikes/ Dickinson, G. (2018). The rise of the dockless bicycle – street litter, or the future of public transport? The Telegraph. Retrieved from https://www.telegraph.co.uk/travel/news/are-dockless-bikes-the- future/ District of Columbia. (2019). Permit application instructions dockless sharing vehicles 2019 mid-year permit. District of Columbia Retrieved from https://ddot.dc.gov/sites/default/files/dc/sites/ddot/ page_content/attachments/MID20YEAR20Permit20Application20Instructions%202019.pdf Elvik, R., & Bjørnskau, T. (2017). Safety-in-numbers: A systematic review and meta-analysis of evidence. Safety Science, 92, 274–282. https://doi.org/10.1016/j.ssci.2015.07.017. Faghih-Imani, A., Anowar, S., Miller, E. J., & Eluru, N. (2017). Hail a cab or ride a bike? A travel time comparison of taxi and bicycle-sharing systems in New York City. Transportation Research Part A: Policy and Practice, 101,11–21. https://doi.org/10.1016/j.tra.2017.05.006. Feng, E. (2018). Asia’s shared-bike sector faces growth headwinds. Retrieved from https://www.ft. com/content/918dfd52-8aee-11e8-b18d-0181731a0340 Fischer, C. M., Sanchez, C. E., Pittman, M., Milzman, D., Volz, K. A., Huang, H., … Sanchez, L. D. (2012). Prevalence of bicycle helmet Use by users of public bikeshare programs. Annals of Emergency Medicine, 60(2), 228–231. doi:10.1016/j.annemergmed.2012.03.018 Fishman, E. (2016). Bikeshare: A review of recent literature. Transport Reviews, 36(1), 92–113. doi:10. 1080/01441647.2015.1033036 730 J. A. HIRSCH ET AL.

Fishman, E., & Schepers, P. (2016). Global bike share: What the data tells us about road safety. Journal of Safety Research, 56,41–45. doi:10.1016/j.jsr.2015.11.007 Fuller, D., Gauvin, L., Kestens, Y., Daniel, M., Fournier, M., Morency, P., & Drouin, L. (2013). Impact evaluation of a public bicycle share program on cycling: A case example of BIXI in Montreal, Quebec. American Journal of Public Health, 103(3), E85–E92. doi:10.2105/ajph.2012.300917 Garikapati, V. M., Pendyala, R. M., Morris, E. A., Mokhtarian, P. L., & McDonald, N. (2016). Activity patterns, time use, and travel of millennials: A generation in transition? Transport Reviews, 36(5), 558– 584. https://doi.org/10.1080/01441647.2016.1197337. Gartenberg, C. (2018). Lime to expand from scooters to shared cars in Seattle. The Verge. Retrieved from https://www.theverge.com/2018/11/13/18092198/lime-car-share-seattle-limepod-expansion- scooter Götschi, T., Garrard, J., & Giles-Corti, B. (2016). Cycling as a part of daily life: A review of health perspectives. Transport Reviews, 36(1), 45–71. https://doi.org/10.1080/01441647.2015.1057877. Graves, J. M., Pless, B., Moore, L., Nathens, A. B., Hunte, G., & Rivara, F. P. (2014). Public bicycle share programs and head injuries. American Journal of Public Health, 104(8), e106–e111. doi:10.2105/ AJPH.2014.302012 Greenfield, J. (2019). Chicago will launch a Pilot with 2,500+ Scooters on June 15, With a Nighttime Curfew. StreetsBlogChicago. Retrieved from https://chi.streetsblog.org/2019/05/01/chicago-will- launch-a-pilot-with-2500-dockless-scooters-on-june-15/ Gu, T., Kim, I., & Currie, G. (2019). To be or not to be dockless: Empirical analysis of dockless bikeshare development in China. Transportation Research Part A: Policy and Practice, 119, 122–147. https:// doi.org/10.1016/j.tra.2018.11.007. Hardin, G. (1968). The tragedy of the commons. Science, 162(3859), 1243–1248. doi:10.1126/science. 162.3859.1243 Harris, M. (2018). The bike share war is shaking up Seattle like nowhere else. Wired. Retrieved from https://www.wired.com/story/the-bike-share-war-is-shaking-up-seattle-like-nowhere-else/ Heffernan, E. (2018). Were some of St. Louis’ new shared bikes thrown into the Mississippi River already? St. Louis Post-Dispatch. Retrieved from https://www.stltoday.com/news/local/metro/ were-some-of-st-louis-new-shared-bikes-thrown-into/article_77e79f63-da4b-56ea-bc10- 904cc64af34f.html Hirsch, J., Stewart, I., Ziegler, S., Richter, B., & Mooney, S. (2019). Residents in Seattle, WA Report differential Use of free-floating bikeshare by Age, Gender. Race, and Location. Front. Built Environ, 5, 17. doi:10.3389/fbuil.2019.00017. Ho, S. C., & Szeto, W. (2017). A hybrid large neighborhood search for the static multi-vehicle bike- repositioning problem. Transportation Research Part B: Methodological, 95, 340–363. https://doi. org/10.1016/j.trb.2016.11.003. Hosford, K., & Winters, M. (2018). Who Are public bicycle share programs serving? An evaluation of the equity of spatial access to bicycle share service areas in Canadian cities. Transportation Research Record, 2672(36), 42–50. https://doi.org/10.1177/0361198118783107. Institute for Transportation & Development Policy. (2018). Dockless Bikeshare: What We Know So Far. Retrieved from https://www.itdp.org/2018/01/04/dockless-bikeshare-know-so-far/ Jäppinen, S., Toivonen, T., & Salonen, M. (2013). Modelling the potential effect of shared bicycles on public transport travel times in greater Helsinki: An open data approach. Applied Geography, 43, 13–24. https://doi.org/10.1016/j.apgeog.2013.05.010. Kett, P., Rivara, F., Gomez, A., Kirk, A. P., & Yantsides, C. (2016). The effect of an all-ages bicycle helmet law on bicycle-related trauma. Journal of Community Health, 41(6), 1160–1166. doi:10.1007/ s10900-016-0197-3 Kraemer, J. D., Roffenbender, J. S., & Anderko, L. (2012). Helmet wearing among users of a public bicycle-sharing program in the district of Columbia and comparable riders on Personal bicycles. American Journal of Public Health, 102(8), e23–e25. doi:10.2105/AJPH.2012.300794 Lekach, S. (2018). Uber rolls out new features for biking, car-sharing, and more. Retrieved from Mashable website: https://mashable.com/2018/04/11/uber-carshare-bikeshare-ticketing-data/ TRANSPORT REVIEWS 731

López-Valpuesta, L., & Sánchez-Braza, A. (2016). Going a long way? On your bike! Comparing the distances for which public bicycle sharing system and private bicycles are used. Applied Geography, 71,95–105. https://doi.org/10.1016/j.apgeog.2016.04.003. Mah, N. (2018, March 15, 2018). New in Ballard | designated bike share parking areas. Retrieved from http://sdotblog.seattle.gov/2018/03/15/new-designated-bike-share-parking-areas-come-to-ballard/ McNeil, N., Broach, J., & Dill, J. (2018). Breaking barriers to bike share: Lessons on bike share equity. Ite Journal-Institute of Transportation Engineers, 88(2), 31–35. https://ppms.trec.pdx.edu/media/ project_files/ITE_Jounal_February_2018_Breaking_Barriers_to_Bike_Share_Lessons_on_Bike_ Share_Equity.pdf. Miller, J. (2018). Dallas Bike Mess (@dallasbikemess) • Instagram photos and videos. Retrieved from https://www.instagram.com/dallasbikemess/ Mooney, S. J., Hosford, K., Howe, B., Yan, A., Winters, M. L., Bassok, A., & Hirsch, J. A. (2019). Freedom from the station: Spatial equity in access to dockless bike share. Journal of Transport Geography, 74, 91–96. https://doi.org/10.1016/j.jtrangeo.2018.11.009. Mooney, S. J., Lee, B., & O’Connor, A. W. (2019). Free-floating bikeshare and helmet use in Seattle, WA. Journal of Community Health, 44(3), 577–579. https://doi.org/10.1007/s10900-018-00599-1. National Association of City Transportaion Officials (NACTO). (2019). Shared micromobility in the U.S. 2019. Retrieved from New York, NY: https://nacto.org/wp-content/uploads/2019/04/NACTO_ Shared-Micromobility-in-2018_Web.pdf National Association of City Transportation Officials (NACTO). (2018a). Bike Share in the U.S.: 2017. Retrieved from https://nacto.org/bike-share-statistics-2017/ National Association of City Transportation Officials (NACTO). (2018b). NACTO policy 2018: Guidelines for the regulation and managmenet of shared active transportation. Retrieved from New York, NY: https://nacto.org/wp-content/uploads/2018/07/NACTO-Shared-Active-Transportation-Guidelines. pdf O’Keefe, B. (2018). A Chinese bike-sharing giant is considering a move into car-sharing. Fortune. Retrieved from http://fortune.com/2017/12/05/mobike-bike-sharing-expansion/ Pal, A., & Zhang, Y. (2017). Free-floating bike sharing: Solving real-life large-scale static rebalancing problems. Transportation Research Part C: Emerging Technologies, 80,92–116. https://doi.org/10. 1016/j.trc.2017.03.016. Parkes, S. D., Marsden, G., Shaheen, S. A., & Cohen, A. P. (2013). Understanding the diffusion of public bikesharing systems: Evidence from Europe and North America. Journal of Transport Geography, 31,94–103. https://doi.org/10.1016/j.jtrangeo.2013.06.003. Ricci, M. (2015). Bike sharing: A review of evidence on impacts and processes of implementation and operation. Research in Transportation Business & Management, 15,28–38. https://doi.org/10.1016/j. rtbm.2015.03.003. Rose, M. (2017). People are leaving Spin and LimeBikes in impressively dumb places. Seattle Magazine. Retrieved from http://seattlemag.com/news-and-features/people-are-leaving-spin- and-limebikes-impressively-dumb-places Salazar, D. (2018). Ofo to pull bright yellow rental bikes off Austin streets. Austin Business Journal. Retrieved from https://www.bizjournals.com/austin/news/2018/07/20/unicorn-flees-austin- goodbye-bright-yellow-ofo.html Salomon, A., Kimbrough, G., & Bershteyn, A. (2014). The safety of public bicycle share programs in North America. American Journal of Public Health, 104(11), E4. Shaheen, S. A., Cohen, A. P., & Martin, E. W. (2013). Public bikesharing in North America early operator understanding and emerging trends. Transportation Research Record, 2387,83–92. doi:10.3141/ 2387-10 Shaheen, S., Guzman, S., & Zhang, H. (2010). Bikesharing in Europe, the Americas, and Asia: Past, present, and future. Transportation Research Record: Journal of the Transportation Research Board, 2143, 159–167. https://doi.org/10.3141/2143-20. Shoup, D. (2017). The high cost of free parking: Updated edition. New York: Routledge. https://doi.org/ 10.4324/9781351179782. 732 J. A. HIRSCH ET AL.

Smith, C. S., Oh, J.-S., & Lei, C. (2015). Exploring the equity dimensions of US bicycle sharing systems. In Transportation research center for livable communities. Kalamazoo, MI: Western Michigan University. https://wmich.edu/sites/default/files/attachments/u428/2015/TRCLC_RR_14_01.pdf. Soper, T. (2017). Bike-sharing services Spin and LimeBike let riders use bicycles without smartphone or credit card. GeekWire. Retrieved from Geekwire website: https://www.geekwire.com/2017/bikesharing-services-spin-limebike-let-riders-use-bicycles-without-smartphone-credit-card/ Tchebotarev, E. (2017). With hundreds of millions of dollars burned, The dockless bike sharing market is imploding. Forbes. Retrieved from Forbes website: https://www.forbes.com/sites/evgenytchebotarev/ 2017/12/16/with-hundreds-of-millions-of-dollars-burned-the-dockless-bike-sharing-market-is- imploding/ Ursaki, J., & Aultman-Hall, L. (2016, Jan 12 2016). Quantifying the equity of bikeshare access in U.S. cities. Paper presented at the Transportation Research Board 95th Annual Meeting, Washington, DC. Vaccaro, A. (2018). A bike-share border war has started in Boston - the Boston Globe. The Boston Globe. Retrieved from https://www.bostonglobe.com/metro/2018/05/16/bike-share-border-war- has-started-boston/Hdb22XyWEnQAuh4r8zUdSI/story.html Willis, D. P., Manaugh, K., & El-Geneidy, A. (2015). Cycling under influence: Summarizing the influence of perceptions, attitudes, habits, and social environments on cycling for transportation. International Journal of Sustainable Transportation, 9(8), 565–579. doi:10.1080/15568318.2013. 827285 Xin, F., Chen, Y., Wang, X., & Chen, X. (2018). Cyclist satisfaction evaluation model for free-floating bike-sharing system: A case study of Shanghai. Transportation Research Record, 2672(31), 21–32. https://doi.org/10.1177/0361198118770193. Xu, C., Ji, J., & Liu, P. (2018). The station-free sharing bike demand forecasting with a deep learning approach and large-scale datasets. Transportation Research Part C: Emerging Technologies, 95,47– 60. doi:10.1016/j.trc.2018.07.013 Yanocha, D. (2018). Optimising new mobility services. Paper presented at the International Transport Forum Discussion Papers. Young, S. (2018). Dallas signs off on bike-share and temporary scooter fix. Dallas Observer. Retrieved from https://www.dallasobserver.com/news/dallas-new-bike-share-rules-10845204 Zanotto, M., & Winters, M. L. (2017). Helmet use among personal bicycle riders and bike share users in Vancouver, BC. American Journal of Preventive Medicine, 53(4), 465–472. doi:10.1016/j.amepre. 2017.04.013 Zhang, D., Yu, C., Desai, J., Lau, H., & Srivathsan, S. (2017). A time-space network flow approach to dynamic repositioning in bicycle sharing systems. Transportation Research Part B: Methodological, 103, 188–207. https://doi.org/10.1016/j.trb.2016.12.006. Zhang, L., Zhang, J., Duan, Z.-y., & Bryde, D. (2015). Sustainable bike-sharing systems: Characteristics and commonalities across cases in urban China. Journal of Cleaner Production, 97, 124–133. https:// doi.org/10.1016/j.jclepro.2014.04.006. Zhao, N., Zhang, X., Banks, M. S., & Xiong, M. (2018). Bicycle sharing in China: Past, present, and future. Paper presented at the Proceedings of the Southern Association for Information Systems Conference, Atlanta, GA, USA.