CitiBike Network Analysis
Summer ridership is 19x winter — and the network rewires itself with the seasons. Mapping 204K Citi Bike trips across NYC and Jersey City using Python, NetworkX, and Plotly.
The Question
New York's continental climate receives four distinct seasons. This study observes the relationship between Citi Bike ridership and the frequency of use at different stations to answer the question: is there a significant difference in the ridership of Citi Bikes over the seasons?
Data was sampled from four representative months — February, May, August, and November — corresponding to each season. Rather than comparing absolute volume between months, the analysis focuses on relative activity at docking stations and inter-station connectivity within each month's time frame.
Approach
Each month was modeled as a directed graph using NetworkX, where stations are nodes positioned by their real latitude and longitude. Trips between station pairs become directed edges, weighted by trip count. The graph layout mirrors actual geography — you can see the shape of NYC and Jersey City's waterfront in the network itself.
Using Plotly interactive scatter plots for each month and basic data-munging, we observe which stations gain or lose prominence across seasons. Overlaying connection lines on the scatter plots reveals how inter-station connectivity shifts.
Python, pandas, NumPy, NetworkX, Plotly, Folium, geopandas, shapely, scikit-learn, Matplotlib, Seaborn
Seasonal Networks
Findings
- Summer ridership is ~19x winter. 93,800 trips in August vs 4,881 in February. The system effectively hibernates in winter.
- The active network expands geographically. From 139 stations in February to 218 in August — the system's spatial footprint grows by 57% in warm months.
- People take longer rides in summer and fall. Shorter, utilitarian rides in winter and spring give way to longer recreational trips when the weather allows.
- Hub stations maintain centrality year-round. Newport PATH (5,063 trips in August), 11 St & Washington St, and 14 St Ferry anchor the network regardless of season.