Forum Discussion

Pizzafan457's avatar
Pizzafan457
Resourceful Rider
2 months ago
Solved

Algorithm

Hello, 

It feels like the citi bike angels algorithm typically assigns valuations based on historical performance. 

For example, there is typically a portion of Bed/Stuy and Bushwick that is need of bikes and has -1 and -2 point valuations (needs dropoffs).  Likewise most of Williamsburg and Greenpoint is typically a range of 0 to +3 (needs pickups).  

Meanwhile, there are typically a few stations spruced throughout Williamsburg and Greenpoint with less than 10-20% of bikes available.  

These stations are rarely if ever incentivized with a +1 or +2 (needs drop offs) even though they are in desperate need of drop offs. 

What are the steps being taken to incentivize people to make common sense drop offs that would 

  1. Redistribute bikes to less crowded stations
  2. Reward users to make common sense detours from their typical routes and lead to spread bikes more evenly

Also, what steps are being taken to increase the 2x multiplier time length? What is the benefit of providing people 24 hours to take positive rides? 

What about Citi Bike Angels who use the program more casually a handful of times a week for example? 

What is the point of disincentivizing Citi Bike riders in taking positive rides by including a rapidly expiring multiplier? For me, and many of my friends the 2x multiplier amounts to a pop-up ad than a helpful piece of information that guides my behavior.

The direction to not take Negative rides serves a similar purpose and is much more effective. 

I understand that Lyft may want to incentivize Bike Angels to participate in the program more frequently but it seems burdensome and unrealistic with the way the vast majority of people use the program.

I believe the Citi Bike program would be greatly improved by adjusting the timelines. See my reccomendation below: 

 

  1. 2x Citi Angels timing: 72 hours to take 1 positive ride to maintain the 2x bonus, to take 3 positive rides to reach 3x positive rides
  2. 3x Citi Angels timing: 1 week to take 3 positive rides 

 

Best,

Pizzafan457

  • Lyft_Omar's avatar
    Lyft_Omar
    28 days ago

    Heya Pizzafan457!

    Regarding on how points are assigned, we do look at historical pattern usage and expected flow of bikes! Based on those patterns if we expect to see, let's say hypothetically 10 bikes to come in to a station but 6 being rented out, all within the same hour, that usually means a rider will still get a bike, even if the overall station is low.

    Keep in mind that we're just waking up from a winter slumber where rides naturally go down because people don't want to bike in the cold.

    On your feedback ideas for streaks, our internal teams have played around with this idea but surprisingly found little benefit for it.

    Ideally the goal of the streaks in general is to encourage some bikes within the same day, we'll keep the feedback of extending 2x and 3x streaks to longer lengths if things do change though! 

6 Replies

  • Lyft_Omar's avatar
    Lyft_Omar
    Bike Angels Team

    Heya Pizzafan457, first of all love the name, I too am a fan of pizza. 

    As far as your user feedback and suggestions go, I am going to bring this up internally and see what answers I can find for you!

    Hope to get back to you soon!

  • Pizzafan457's avatar
    Pizzafan457
    Resourceful Rider

    Sounds good Lyft_Omar. I'll stay tuned. Citibike has made my time in NYC a lot better and I appreciate your prompt response and how willing Lyft is to engage with the community

    • Lyft_Omar's avatar
      Lyft_Omar
      Bike Angels Team

      Heya Pizzafan457!

      Regarding on how points are assigned, we do look at historical pattern usage and expected flow of bikes! Based on those patterns if we expect to see, let's say hypothetically 10 bikes to come in to a station but 6 being rented out, all within the same hour, that usually means a rider will still get a bike, even if the overall station is low.

      Keep in mind that we're just waking up from a winter slumber where rides naturally go down because people don't want to bike in the cold.

      On your feedback ideas for streaks, our internal teams have played around with this idea but surprisingly found little benefit for it.

      Ideally the goal of the streaks in general is to encourage some bikes within the same day, we'll keep the feedback of extending 2x and 3x streaks to longer lengths if things do change though! 

  • Pizzafan457's avatar
    Pizzafan457
    Resourceful Rider

    Hi Omar, 

    First, I appreciate your answer. This is really helpful and answers my question. I would like to bring one other scenario to your attention on this topic while we are discussing the algorithm. 

    I hear you on how points assigned and it feels like the generally right idea. I think in practice I've seen stations around me with 0-4 bikes for extended periods of time (30 minutes at least) without a neutral point value.  This feels wrong to me. Also, I rarely if ever see a -2 or -3 designation in Williamsburg or Greenpoint even if there are no bikes available at the station. 

    I understand that on average the algorithm expects more bikes to arrive at that station than for bikes to be borrowed (net surplus) but in reality people who would borrow a bike don't have that option for the short term. It feels like there are at time surges in usage that result in stations that temporarily have no bikes. 

    1. How does the algorithm handles these surges in usage that seem to fall outside of normal seasonal patterns you described above?
    2. If you're able to share, what are the criteria that would lead to a station receiving a -2 or -3 categorization (moderate need for dropoffs and strong need for dropoffs)? It seems like these categorizations are almost never assigned in Williamsburg and Greenpoint. 

    Thanks for your attention here!

     

    Best,

    PF

    • Lyft_Omar's avatar
      Lyft_Omar
      Bike Angels Team

      Heya Pizzafan457!

      Unfortunately I am able to share in-depth details regarding how the algorithm works besides what I shared in my previous reply. Essentially though, it is the same answer of historical data pattern usage.

      As for the Greenpoint/Willliamsburg areas, I have flagged this to our internal teams just to keep an eye on our for if anything is acting a bit funky.

  • Pizzafan457's avatar
    Pizzafan457
    Resourceful Rider

    Thanks Lyft Omar. Could you say if it's possible for a station to have a -2,-3,-4 assigned to it or has this feature been removed? A few years ago I would sometimes see these values but not so much now.