Geography, movements, and other tidbits from Boulder’s B-cycle bike sharing system

I put together an analysis of the 2013 Boulder B-cycle data and wanted to share a few interesting tidbits! Here’s a link to a PDF of the full presentation for anyone who wants dive right in: Boulder B-cycle 2013 Analysis


as a person in a city

I want to understand the layout/flows of bikeshare systems

so I can move around efficiently

System Layout

In 2013, the Boulder B-cycle system had:

  • 22 Stations
  • 276 Docks
  • 138 Bikes

The largest station had seventeen docks while the smallest had nine. Note the large grey dot which marks the geographic center of the system, which did not have a station in 2013 (but does now!)

2013 station layout

Elevation and distance from the center:

2013 Station distance from center and elevation

System Usage

The basic 2013 Boulder B-cycle usage statistics:

  • Total 2013 rides: 28,256
  • Median duration: 14 min
  • Median distance*: .77 mi

Note that distance is calculated “as the crow flies” and understates actual distance traveled, but can be useful as a proxy for distance.

Here’s a map showing each station, with the largest bubbles having the most in/out trips while the smallest have the least:

2013 most active stations map


Right away, we notice that the two most likely indicators of trip count are both proximity to downtown Boulder and proximity to the geographic center of the bike-sharing system.

The majority of trips are under 60 minutes and travel less than 1.5 miles.

2013 Distance and Duration


On an hourly basis, total bicycles checked out peaks at 11AM and has a second, lesser peak at 5PM. Casual users peak gradually in the mid-afternoon while annual users patterns are less uniform. Also note that Boulder B-cycle was only available between 5AM and midnight in 2013.

2013 24-hour usage profile


When accounting for day of week, we see more and later-in-the-day usage toward the end of the workweek. And total usage on weekends for all users more closely mimics that of casual users in general.

2013 24-hour usage profile per day

But another interesting question – how does this usage change in different seasons, with sunlight and temperature likely being big factors?

In the colder/darker months, September through April, we see a much sharper usage pattern that focuses on warm daylight hours:

2013 24-hour September through April

In the summer, we see a much wider usage pattern, extending more heavily into the evening, with many more total riders:

2013 24-hour May through August

We see total ridership reflected in the next graph, with significant increases in the summer months (much of the increase reflecting many tourists in Boulder):

2013 Daily Rides


Station Usage Factors

Since we’ve looked at total rides, now let’s look at where people ride to/from the most. Bike-sharing is point-to-point instead of out-and-back, the system allows for net increases or decreases in the number of bikes available at any given station (which requires system rebalancing).

Stations with large bubbles marked in green are net positive in bikes, and small bubbles in yellow/orange are net negative in bikes:

2013 flows map


Let’s look at some of the factors that may be in play to explain why stations are net positive or net negative.

We see there’s a correlation between distance from center and a net decrease in bikes at a station.

2013 station net change vs distance from center


Another attribute we’d like to test is station elevation. This chart shows an inverse correlation between station elevation and net change in bikes. There may be several factors at play, but generally people have an easier time riding downhill than up.

2013 station net change vs elevation

Other Usage Factors

How sunlight trends with ridership.

2013 Daily Rides vs sunlight

How high temperature affects ridership.

2013 Daily Rides vs temperature

How precipitation affects ridership. Yes, Boulder did get 9 inches of rain on Thursday, September 12th, 2013, during the history flooding event.

2013 Rides vs precipitation

A closer look at ridership during the 2013 flooding:

2013 September Rides vs precipitation

Hopefully this helps understand a bit more about the bikesharing patterns in Boulder. The system has since added many more stations so I’ll hope to update some of the graphs in the future to see how things change. Please send me a comment or note if you have any questions!

@ericmbudd on Twitter.


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