6 ms·

Balancing Bike-Share Stations Has Become a Scientific Endeavor

35 points by wallflower 12y ago

jpfr 12y ago
I recently published on the same topic. [1] In many bike sharing systems (such as in London), there is a daily repeating cycle, where too many people want to get to the city center in the morning and back out in the early evening. You know that will happen. So countermeasures can be taken early on. [1] Dynamic Vehicle Redistribution and Online Price Incentives in Shared Mobility Systems, http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=6754195 http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumb...
- toomuchtodo 12y ago
  How does London handle that rebalancing then? Physically moving bikes with a lorry?
  - jpfr 12y ago
    At one point they had nearly 30 repositioning trucks in London (2-3 years ago). At Waterloo Station they basically hand them off trucks directly to the arriving customers during rush hour.
- sliverstorm 12y ago
  Why is this a problem? If X people take bikes into the city center in the morning, and then the same X people take bikes back out in the evening, that sounds balanced to me.
  - skybrian 12y ago
    That only works if there are enough bikes for each bike to be used only once during the morning or evening commute. If you need to reuse a bike multiple times in one morning (say at 8am, 9am, and 10am) to serve everyone, it has to somehow go where someone will use it.
gst 12y ago
Most of the current systems appear to use manual rebalancing - if bikes aren't evenly distributed someone from the company operation the bike share program manually distributes bikes from one station to another station. I wonder how well an "economic" approach to this problem would work: Dynamically price the cost of a bike based on the station where the bike is taken and on the station where the bike is returned too. Then, if you want to distribute bikes from one station to another station you could assign a negative price for these routes, and thereby increase the traffic in that opposite direction. Assuming that the traffic behavior is relatively stable you don't even need dynamic pricing, but instead might be able to announce the pricing for a particular route weeks in advance.
- jpfr 12y ago
  See the paper linked in the post below. It deals with exactly that 'economic approach' in addition to traditional repositioning with trucks. But with positive customer incentives instead of added costs. There's a freely accessible preprint on arxiv under the same title if you cannot cross the paywall. By the way, incentives do not need to be monetary. In Paris, they give people free minutes for driving bikes to stations that are uphill...
- zheshishei 12y ago
  I came here to point out this exact same thing. Why use vans and trucks to re-balance stations when you can have people re-balance them? Not only can you can have dynamic pricing based upon stations and times, imagine having a feature where you can "call" for a bike at an empty station. There can be an app that notifies people near other close non-empty stations to ride a bike over for you. Or, you could even display it on the screen of the kiosk. How would you get people to ride these bikes for re-balancing or on demand? Offer something like a rewards plan (re-balance a bike X number of times and receive a discount on your next bike rental) or pay them in micro-payments (Think Tom Hanks returning luggage trolleys in The Terminal). How could you ensure that people riding bikes on demand don't take advantage of the process to just get a free ride to wherever? First, make sure that the bike being taken out is checked into the station it's being delivered to. Second, impose some sort of time limit in which that needs to be done. Base the time limit on an acceptable pace and take into account the distance between the stations (with a time buffer). If it exceeds that limit, it becomes a regular rental and the deliverer is charged regularly. Also, it then becomes possible to add bonus incentives for getting the bike to the station faster. One particular bonus of this system is that it can leverage a city's homeless population as a workforce. (If you disagree due to cleanliness issues, I'm sorry to tell you that the homeless already use citibikes as cycling machines). Of course, there would be a need to hedge against the possibility they may just take out a bike and never return it, since they don't really have any sort of credit. One possibility would be to sponsor a homeless person by covering the cost of a bike and then having them operate on a "one strike" policy.
robrenaud 12y ago
Maybe the real solution is social rather than technical? How many move around to different places for the sake of internet points? Seemingly lots of them. http://en.wikipedia.org/wiki/Ingress_(game) http://en.wikipedia.org/wiki/Ingress_(game) Can we just convince them to balance our bike shares instead?
pkaye 12y ago
How do these systems work if there are not enough stations to return your bike?
gevz 12y ago
I wonder how this problem is solved by car2go. There are no stations to drop the vehicle, and cars can not be transported in bulk. Would it help to get rid of the stations for the bikes?
- wuschel 12y ago
  In Germany, Call-a-bike (Deutsche Bahn) [1] operates exactly like this. Bikes can be rented everywhere inside the city, and can be left on every junction within a city. There are no drop-off/rental stations. So far, I did not have any problems to find a bike when I needed it. [1] http://www.bahn.de/p/view/service/fahrrad/call_a_bike.shtml http://www.bahn.de/p/view/service/fahrrad/call_a_bike.shtml

35 points by wallflower 12y ago

jpfr 12y ago

I recently published on the same topic. [1] In many bike sharing systems (such as in London), there is a daily repeating cycle, where too many people want to get to the city center in the morning and back out in the early evening. You know that will happen. So countermeasures can be taken early on. [1] Dynamic Vehicle Redistribution and Online Price Incentives in Shared Mobility Systems, http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=6754195 http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumb...

toomuchtodo 12y ago
How does London handle that rebalancing then? Physically moving bikes with a lorry?
- jpfr 12y ago
  At one point they had nearly 30 repositioning trucks in London (2-3 years ago). At Waterloo Station they basically hand them off trucks directly to the arriving customers during rush hour.
sliverstorm 12y ago
Why is this a problem? If X people take bikes into the city center in the morning, and then the same X people take bikes back out in the evening, that sounds balanced to me.
- skybrian 12y ago
  That only works if there are enough bikes for each bike to be used only once during the morning or evening commute. If you need to reuse a bike multiple times in one morning (say at 8am, 9am, and 10am) to serve everyone, it has to somehow go where someone will use it.

gst 12y ago

Most of the current systems appear to use manual rebalancing - if bikes aren't evenly distributed someone from the company operation the bike share program manually distributes bikes from one station to another station. I wonder how well an "economic" approach to this problem would work: Dynamically price the cost of a bike based on the station where the bike is taken and on the station where the bike is returned too. Then, if you want to distribute bikes from one station to another station you could assign a negative price for these routes, and thereby increase the traffic in that opposite direction. Assuming that the traffic behavior is relatively stable you don't even need dynamic pricing, but instead might be able to announce the pricing for a particular route weeks in advance.

jpfr 12y ago
See the paper linked in the post below. It deals with exactly that 'economic approach' in addition to traditional repositioning with trucks. But with positive customer incentives instead of added costs. There's a freely accessible preprint on arxiv under the same title if you cannot cross the paywall. By the way, incentives do not need to be monetary. In Paris, they give people free minutes for driving bikes to stations that are uphill...
zheshishei 12y ago
I came here to point out this exact same thing. Why use vans and trucks to re-balance stations when you can have people re-balance them? Not only can you can have dynamic pricing based upon stations and times, imagine having a feature where you can "call" for a bike at an empty station. There can be an app that notifies people near other close non-empty stations to ride a bike over for you. Or, you could even display it on the screen of the kiosk. How would you get people to ride these bikes for re-balancing or on demand? Offer something like a rewards plan (re-balance a bike X number of times and receive a discount on your next bike rental) or pay them in micro-payments (Think Tom Hanks returning luggage trolleys in The Terminal). How could you ensure that people riding bikes on demand don't take advantage of the process to just get a free ride to wherever? First, make sure that the bike being taken out is checked into the station it's being delivered to. Second, impose some sort of time limit in which that needs to be done. Base the time limit on an acceptable pace and take into account the distance between the stations (with a time buffer). If it exceeds that limit, it becomes a regular rental and the deliverer is charged regularly. Also, it then becomes possible to add bonus incentives for getting the bike to the station faster. One particular bonus of this system is that it can leverage a city's homeless population as a workforce. (If you disagree due to cleanliness issues, I'm sorry to tell you that the homeless already use citibikes as cycling machines). Of course, there would be a need to hedge against the possibility they may just take out a bike and never return it, since they don't really have any sort of credit. One possibility would be to sponsor a homeless person by covering the cost of a bike and then having them operate on a "one strike" policy.

robrenaud 12y ago

Maybe the real solution is social rather than technical? How many move around to different places for the sake of internet points? Seemingly lots of them. http://en.wikipedia.org/wiki/Ingress_(game) http://en.wikipedia.org/wiki/Ingress_(game) Can we just convince them to balance our bike shares instead?

pkaye 12y ago

How do these systems work if there are not enough stations to return your bike?

gevz 12y ago

I wonder how this problem is solved by car2go. There are no stations to drop the vehicle, and cars can not be transported in bulk. Would it help to get rid of the stations for the bikes?

wuschel 12y ago
In Germany, Call-a-bike (Deutsche Bahn) [1] operates exactly like this. Bikes can be rented everywhere inside the city, and can be left on every junction within a city. There are no drop-off/rental stations. So far, I did not have any problems to find a bike when I needed it. [1] http://www.bahn.de/p/view/service/fahrrad/call_a_bike.shtml http://www.bahn.de/p/view/service/fahrrad/call_a_bike.shtml