Looking into Citi Bike’s First Summer and Winter: July 2013 and January 2014
Citi Bike, a privately owned, public bicycle-sharing system, has been deemed a popular transportation mode in New York over the years since its inception. Citi Bike was opened on May 27, 2013 — having 332 initial stations with 6,000 bicycles.
Upon looking into the publicly available data of Citi Bike, It was strategic that Citi Bike launched on the cusp of Spring and Summer (of 2013), where the seasons change from cold to hot. In this sense, it is expected that there is more access to riders (i.e., more people out on hotter days), hence more marketability, for the new service at that time.
This article aims to describe and show the behaviours of the Citi Bike system in New York City, during its early days by performing visualizations and analysis of the Citi Bike trip data. For the analyses of data, I chose July 2013 to represent the Summer 2013 season, since it is on average, the hottest month of the year. Likewise, I also chose January 2014 to represent the Winter 2013/14 season, since it is on average, the coldest month of the year, and the month where snow falls the most.
Summary Statistics: July 2013 (Summer) vs. January 2014 (Winter)
1. Total Time of the Trip Durations
In comparing the two months, July 2013 (841814103 seconds), in summer, has almost 4 times more total trip hours than January 2014 (220484271 seconds), when it was winter.
It can be inferred that riders have a seasonal preference to ride in bikes, i.e. when the weather is better. In accounting for safe biking conditions, it can be also inferred that most biking trips happen in day time (more sun means more light), and in winter, sunlight is significantly less (more dangerous to cycle in the dark in under snow).
2. Mean time for Trip Durations
The same can be said for the trends in mean trip duration. Trip times in January 2014 are significantly less than that of July 2013’s. Perhaps, the trips in winter are more of essential purposes (e.g. deliveries, trips to pharmacies etc., where proximity is generally lesser), compared to trips in summer where biking trips are more recreational, and bikers tend to have longer tolerance in sunnier weather conditions than in harsh winter conditions.
3. Minimum and Maximum Time for Trip Durations
Minimum trip durations for both months remain standard. That is, the nature of the bike trip with least time is probably the same in both summer and winter conditions. Of course, it is again expected that trips would last longer in summers, hence having the maximum trip duration of July 2013 is tripled than of January 2014’s.
4. Date and Day Trends in Biking
4.1 Daily Bike Trips
The time series graphs show the trends of daily bike rides over the course of the month of July 2013 versus July 2014.
Interestingly, July 2013 has an upward trend of ridership going until the end of July to August 2013. Does this mean that Citi Bike has been increasing its ridership? This trend can also reflect the business performance of Citi Bike in its initial establishing months in New York City. The hottest day of the year (in NYC) is July 18, 2013, we see that trips on that day are about the month’s average day trips.
The lowest ridership for January 2014, is on January 3, which actually coincides with the first snowstorm of the 2013/14 winter season. Most people have averse going out, or probably have preferred alternative transportations that can be adaptable to snow storm conditions.
4.2 Bike Trips on the Day of Week
For July 2013, ridership was most prominent on Wednesdays, but ridership actually drops towards the weekend. Perhaps riders also use Citi Bike as transportation for work-related travels during the weekdays. Interestingly though, for January 2014, it is almost the opposite trend, later in the week, ridership increases.
5. Usership of Bike Riders
The usership of bicycles in July 2013 were both subscribers and customers, whereas for July 2014, the usership was predominantly subscribers. This can infer two things: over the period between summer and winter in 2013, customers have become subscribers, and/or the users who ride during winter are mostly the ones who heavily rely on Citi Bike for daily/essential travels, which are subscribers (versus customers who mostly ride Citi Bike casually).
6. Gender of Bike Riders
It is also observed that the gender of the bicycle drivers are male: does this imply that more men use bicycles than women? Or, does the nature of the trips have more affiliation towards men (i.e. deliveries)?
Spatial Analyses of Citi Bike Stations
1. Distribution of Citi Bike Stations in its early phase (2-month mark since opening)
The map shows the distribution of Citi Bike stations in its first opening phase in summer of 2013, Upon analyzing the data, there were only 25 Neighborhood Tabulation Areas where Citi Bike stations are located. The Citi Bike stations are clustered from Midtown to Downtown of Manhattan, and in the left part of Brooklyn, bridging to Manhattan.
2. Distribution of Citi Bike Stations in regards to Tourist Attractions (Manhattan and Brooklyn)
The map shows the distribution of the Citi Bike stations is strategically located near tourist areas (mostly Midtown to Downtown) in Manhattan and Brooklyn. The stations in Manhattan and Brooklyn are mostly well connected to each other since there are tourist attractions serving as transitions spaces, and the stations are concentrated near the bridges connecting Manhattan and Brooklyn.
3. Distribution of Citi Bike Stations in regards to Subway Stations/Lines
One would expect that Citi Bike stations would be further from subway lines to compensate for the (lack of reach) of some subway stations. But however, it does not seem the case. There are bike stations along the subway lines, and near the subway stations. Perhaps, this actually improves connectivity for riders, where using Citi Bikes to go to and from subway stations.
4. Number of Citi Bike Trips per Neighborhood Tabulation Area
The choropleth maps show the ranking where the starting trips start the most (based on NTA), and for July 2013, bike trips start at Chelsea the most, and bike trips also start prevalently in Lower Manhattan (West side).
The start trips in Midtown (West side) is about equal to the number of start trips in Chelsea in January 2014.
Comparing both maps, perhaps the concentration of the initial customers are in the Chelsea area, then has expanded to upper Midtown. Also, there are more start trips in Brooklyn in July 2013 than January 2014.
5. Mapping Median Incomes per Neighborhood Tabulation Area
Was “demographics’ income” a metric for Citi Bikes to situate their stations? Perhaps so. The Chelsea and Midtown areas are ranked to have the highest median income across New York City, the same for Brooklyn where there are bike stations situated in the area with higher median income.
A strategy that Citi Bike deployed was to probably capture the demographics who would have proper access to technology (with higher income), who can access the Citi Bike application, and who have higher inclination to ride bikes for fitness and for travels (demographics with extra income for bike rides, not just relying on public transportation systems).
- The data I used was from the ACS Surveys of 2010–2012 (before 2013), perhaps the data the Citi Bike operators used for planning their stations prior to opening.
6. Measuring the Usage of Existing Citi Bike Stations
Seen in the interactive map below, shows the usage of stations across NYC for July 2013. Observation: There is more usage of bike stations in Manhattan, specifically Midtown. Brooklyn has less bike and station usage compared to Manhattan (this correlates to the bike trips’ choropleth maps).
These analyses can help the operators of Citi Bike (Motivate), to infer how to manage their bike stations — where to add stations for expansions or remove stations if necessary.
This however is something to think about: when stations expand across the city… will the usage of each particular lessen or not?
In conclusion, Citi Bike has performed well in its first Summer and Winter seasons, with stations readily available in “popular” areas in Manhattan and Brooklyn. Another story to be looked at is how Citi Bike has expanded over the years, running in its seventh year today.
Bibliography
Data Sources
Citi Bike NYC. (2020). Citi Bike System Data. Retrieved from https://www.citibikenyc.com/system-data
Geopandas. (2020). New York City Boroughs. Retrieved from Geopandas library
NYC Transportation Department. (2020). Provided in the Urban Informatics I course
NYC Transportation Department. (2020). Subway Stations. Retrieved from https://data.cityofnewyork.us/resource/kk4q-3rt2.json
My GeoData Cloud. (2020). Kings Country Tourist Attractions, Open Street Map. Retrieved from https://mygeodata.cloud/data/download/osm/tourist-attractions/united-states-of-america--new-york/kings-county
My GeoData Cloud. (2020). New York Country Tourist Attractions, Open Street Map. Retrieved from https://mygeodata.cloud/data/download/osm/tourist-attractions/united-states-of-america--new-york/new-york-county?fbclid=IwAR0GFwty5Iu33L56yH8pbQK6YilRhcmhNtrzYKMj821ALd0aNzaa7igM4Ws
GeoDa Data and Lab. (2013). Neighborhood Tabulation Area American Census Survey Demographic Data. Retrieved from https://geodacenter.github.io/data-and-lab/NYC-Nhood-ACS-2008-12/?fbclid=IwAR2pRsKwOPUe_2SBWjyihSRuodXHegqxbms07bEEGzdxUdTf-8u1pZuqMYE
References
Citi Bike NYC. (2020), About Citi Bike. Retrieved from https://www.citibikenyc.com/about
Current Results. (2020). New York City Annual High Temperature. Retrieved from https://www.currentresults.com/Yearly-Weather/USA/NY/New-York-City/extreme-annual-new-york-city-high-temperature.php
Minchillo, J. (2014). First major winter snowstorm of 2014. Retrieved from https://www.cbsnews.com/pictures/first-major-winter-storm-of-2014/