A guide to customized sampling plans for National Transit Database reporting


Xuehao Chu

Document Type

Journal Article

Publication Date


Subject Area

planning - surveys


For estimating the system total unlinked passenger trips and passenger miles of a fixed-route bus system for the National Transit Database (NTD), the sampling plans approved by the Federal Transit Administration (FTA) may either over sample or do not yield FTA’s required confidence and precision levels for the specific conditions of a transit agency. This guide helps transit agencies avoid these problems by developing sampling plans customized to their fixed-route bus services. Detailed steps are provided to calculate the statistical variation in passenger miles and unlinked passenger trips and the correlation between them.

This guide complements FTA Circular C2710.1A in that transit agencies first select one of their own sampling plans that best meets their staffing needs, and then follow the procedures in the circular on sampling and collecting field data. Transit agencies should be able to use this guide and the related calculations as an approval of a qualified statistician as required by the current NTD reporting manuals.


Permission to publish the abstract given by the Journal of Public Transportation.