Data

The CitiBike trip data is publicly available from their website. For our analysis, we used the trip data for March 2015, June 2015, July 2016 and December 2016. Since we only wanted to compare the ridership based on the user type, we only retained the start date of the trip and the user type. For easier categorization and plotting, subscribers are coded as 1 and customers as 0. 
Since we wanted to compare the ridership on weekdays against weekends for each user type, we did an initial visualization by aggregating the data based on the day of the week for each user type using the absolute counts.