Foursquare ITP applied interpolation methods and data quality checks to Automatic Passenger Counter (APC) data to calculate key figures that CATS reports to the National Transit Database (NTD). CATS engaged Foursquare ITP to estimate total and average UPT and PMT for weekdays, Saturdays, and Sundays by month. Our approach, based on the National Center for Transit Research (NCTR) guidebook “Guidebooks for Estimating Total Transit Usage Through Extrapolating Incomplete Count,” interpolated missing trips in a statistically reliable way that would be accepted by FTA.
CATS engaged Foursquare ITP to estimate total and average UPT and PMT for weekdays, Saturdays, and Sundays by month. Our approach, based on the National Center for Transit Research (NCTR) guidebook “Guidebooks for Estimating Total Transit Usage Through Extrapolating Incomplete Count,” interpolated missing trips in a statistically reliable way that FTA would accept. The methods developed by Foursquare ITP are also reusable for future reporting months and years. CATS submitted its NTD figures for UPT and PMT on time, with confidence that its interpolation methods had been reviewed and approved by a qualified statistician.
Solutions and Outcomes
- Developed a new methodology to interpolate missing ridership data for trips that did not have APC data.
- Conducted a thorough data quality review of APC data, including statistical tests of equivalence between APC counts and manual ridechecks.
- Led review by a qualified statistician of the methodology, ensuring results can be used for NTD reporting.