The potential impact of high density docking stations on Bike Share distribution activities Biella Research June 2016

Transcription

1 The potential impact of high density docking stations on Bike Share distribution activities Biella Research June 6 Dr harles arey

2 Summary This paper demonstrates that the traditional bike share design requirement of docking spaces per bike can impose a considerable constraint on system operation. Increasing this ratio has the potential to significantly reduce bicycle distribution with consequent reductions in operating costs. Furthermore docking stations are characterised into different groups which help the assessment of potential savings that increased capacity might bring. Introduction While docking stations can typically range from having to 4 docking spaces per station, the ratio of total docking spaces to number of bikes in any given scheme is remarkably consistent with most current bike share schemes across Europe, the US and South America, providing to.5 docking spaces per bicycle (Ref, ). Biella Research has undertaken a number of studies on European cities and found that increasing this ratio has the potential to significantly reduce distribution visits which in many cases account for around 5% of yearly operating costs. This report follows a preliminary inspection of the data supplied by Transport for London over a representative time period in 4. Data has been inspected for the four week period between the end of May through to June 4. This is early summer and is considered a period which reflects a balanced degree of cycle hire activity amongst daily casual users and annual members, avoiding the anomaly of extreme weather periods and holiday periods. ase studies London has one of the largest bike share schemes outside hina with ca, bikes and, docking spaces distributed across over 7 stations. Three types of docking station have been identified and selected for further analysis : A. large Railway stations, Waterloo and Kings ross, which demonstrate very large daily commuter swings with relatively low drift (defined as when a station demonstrates a bias towards emptying or filling over the course of a day). B. stations which have very high drift, Stonecutter St and Hop Exchange, Borough, both tending to fill during each day but not empty in the evening.. 3 entral London stations which have a noticeable daily swing with periodic drift. A B A B Figure : Location of stations under study

3 Each station has been analysed for the number of bikes taken and returned by users across the four week period ignoring distribution with bulk removal and deposit by the system operator. The data is presented in graphical form as highlighted in Figure. In order to aid comparison, the number of bikes being removed or deposited at any one station has been normalised to the size of the docking station under study. Thus for Waterloo is equivalent to all three stations sited at Waterloo totalling 6 docking spaces, whereas for Aldersgate St, is equivalent to 5 docking spaces. It should be noted that in reality, the NET number of bike movements can only lie between (an empty station) and (a full station), but when distribution activity is removed the GROSS number of bike movements can be more than or even negative if there is a continual removal of bikes. By displaying GROSS activity one can observe the underlying trend of a station across a period of time where large swings greater than indicate a high amount of distribution activity. The x-axis is the number of events at a station, bike deposit or withdrawal, that occur over the time period under study. Actual figures have been removed to avoid confusion, and time is represented by the red vertical lines highlighting midnight for each day. Thus two red lines close together signify that not much activity occurred at the docking station over the course of that day. Each graph covers the same time period of 6 days in May/June 4. normalised number of bicycles ie = dock station size weekends bike activity 3 times capacity of existing dock station 5 May June 4 Figure : Bike activity at Waterloo Station Finally, the overlaid grey band demonstrates the impact of a station three times the size of the existing station. If this band encompasses a significant portion of the Gross movement, the implication is that significantly less distribution is required to keep the stations supplied with bikes, or more importantly, prevent stations from becoming full. For each graph, the average number of distribution visits per week is included to give an indication of activity required to keep the station supplied with bicycles and avoid stations being full over long periods of time. Fig shows the location of the stations in the study which do not show an even geographical spread but were chosen as representative of medium to high usage stations with high distribution requirements and distinctive characteristics.

4 Type A station : ommuter travel hub - high activity, low drift Waterloo Station - 5 visits/wk 4 Belgrove St, Kings ross - 7 visits/wk Both stations demonstrate the typical daily commute associated with a railway terminus, showing very large withdrawals in the morning and large deposits in the evening. Weekend activity is less (narrower bands reflecting less activity), but relatively consistent throughout the day. The implication for this type of station is that an infinitely large station would effectively auto redistribute requiring no intervention whatsoever. Waterloo Station is to some degree an exception due to its size and nearby bike storage hub which enables rapid supply and removal of bikes. That said, it can be seen that a station with three times as many docking spaces would cover much of the daily movement. Of course one would have to factor in the impact of a larger station encouraging more activity, but whereas this might reduce the impact of a larger station it is unlikely to negate it altogether. The smaller station size of Belgrove St ( vs 6) shows much larger swings relative to dock size, and a denser station would have less impact on distribution. That said, it is understood the site has no hub, so even small reductions in visits could be useful, especially if vehicle access is difficult for operators to load and unload bikes. While Waterloo is evenly split between bike collection and bike deposit, some two thirds of Belgrove distribution activities are collection. Type B station: High activity, high drift Stonecutter St - 5 visits/wk Hop Exchange, Borough - visits/wk Both these stations demonstrate a strong drift to depositing bikes in the morning but not withdrawing them in the evening. This is confirmed with collection visits accounting for 85% and 99% of distribution activities for Stonecutter St and Hop Exchange respectively. While Stonecutter St is clearly a commuter site (noticeable reduction in weekend activity), Hop Exchange shows good usage over the weekend. With these stations, more docking spaces would reduce operator visits, possibly to one per day, but this would not remove the tendency to drift which will be driven by other demographic attributes of the station siting. 3

5 Type station: Medium activity, periodic drift 3-7 Aldersgate St - 6 visits/wk Queen St, Bank - 6 visits/wk These stations show periodic drift over time for differing reasons. In the case of Queen St, there appears to be a rise in bikes taken Friday afternoon, but not deposited on Monday morning which might reflect weekly commuter habits. In contrast, Exhibition Rd reflects the variable nature of a site used by museum visitors with high usage on some weekends. All stations show typical central London Exhibition Rd Museums - 9 visits/wk daily trends with increasing deposits in the morning followed by withdrawals during the afternoon. Distribution activities are more or less evenly spread between collection and deposit for all three stations. A high capacity station should benefit all three locations, potentially avoiding visits over a period of several days, although an operator would need to plan for unpredictable swings in usage. All the stations studied show distribution visits by the operator of more than seven per week (ie at least once a day) and this is a relatively high frequency which is reflected in over 4 other stations (ca %) of a total of 733 stations. These stations account for over half the distribution activities over the period in question with the remaining 5 or so stations requiring less distribution per station. onclusion The analysis confirms the intuitive view that increasing the capacity of a bike share scheme will have a significant impact in reducing distribution activities. Even stations with high drift can benefit from increased capacity although the cost/benefit may be less attractive: this is also possibly true of stations in hilly bike share schemes not studied here, where elevation results in strong drift (cyclists tend to prefer going down hills). Because urban space constraints and capital costs generally prevent larger stations being deployed, schemes have tended to settle on the bike : /,5 docking space ratio. This is a potential oversight, and can be addressed by the implementation of low cost, high density docking stations. These are being developed by Biella Research with a view to further promoting the expansion and uptake of Bike Share across existing and new schemes. Acknowledgements: Biella Research is grateful to Transport for London for the contribution of data for this work. Ref : ITDP Bike Share Planning Guide Dec 3 Ref : Obis Optimising Bike Share in European ities - A Handbook June 4