Monthly Archives: July 2014

July 2013 Citibike Breakdown

Citi Bike in New York City makes available some limited system data on a month by month basis. Here, I take a look through the data for July of 2013 and try to extract a better understanding of the users of the largest bike share program in the United States.

First, I wanted to know just where are the docking stations for Citi Bike, and which docking stations saw the most use. The map below illustrates this:


Use Map


Citi Bike only covers a small portion of the area of New York City, Manhattan below central park and very limited portions of Brooklyn. We can see that use in Brooklyn and Alphabet City is significantly less than the other areas of coverage.

Next, I wanted to know when people use Citi Bike the most, and for how long. The graph below shows start time of Citi Bike trips by hour. The color represents the average duration of the trips that began in each hour.


Starttime by hour w trip duration



And now a similar graph with the end time of trips.


Endtime by hour w trip duration



Mostly, we see what we would expect. The spikes occur when people are commuting to and from work. We can even see how many people start their trip for work in the 8:00 hour and arrive in the 9:00 hour, with a similar phenomenon in the afternoon during the 5:00 and 6:00 hours. We also see that those rides in the small hours of the morning tend to be the longest.

Next, I wanted to know some more about the demographic of the riders. Below is a graph showing the breakdown of Citi Bike annual subscibers by birth year.


Number of Records by Birth Year



We can see that Citi Bike is most popular with people ages 25-40, and especially so with people who are 29-35.

Now we explore the Gender break down. Also, I looked into how gender correlates with the average trip duration.


Number of Records by Gender w Average Trip Duration



We can see that males more than triple females in the number of subscribers, and they tend to have slightly shorter trip durations. Keep in mind that this still only applies to annual subscribers. One time customers are not required to give their personal information.

So, how much of the use of Citi Bikes is devoted to the annual subscribers?


Number of Records by Subscriber Type with Average Trip Duration


Subscribers account for nearly quadruple the number rides taken.

In a short time, from limited data, we now have a better understanding of the users of New York City’s bike share program.

Frequency of Soyuz Launches

The International Space Station has been serviced by two manned spacecraft, the American Space Shuttle and the Russian Soyuz. Since the decommissioning of the Space Shuttle Program, the Soyuz remains the only spacecraft to transfer crew members to and from the ISS. I wondered how the retirement of the Space Shuttle effected the launch rate of the Soyuz spacecraft. The bar graph below illustrates the frequency of Soyuz launches beginning with the first manned mission to the ISS.


Frequency of Soyuz Launches


Beginning in 2009–two years before the decommissioning of the Space Shuttles, but only one year before their scheduled decommissioning–the Soyuz spacecraft jumped from making a steady two launches per year to four launches per year. The staggering shown toward the right of the graph represents the Russian Federal Space Agency’s tendency to launch two spacecraft in quick succession, wait a while, then launch two more.

The continuing development of the Dragon V2 spacecraft and others like it, as well as mounting tensions with Russia will likely impact the way astronauts and cosmonauts travel to and from space in the near future.