MAKING IT USEABLE    Interpreting Estimates       The NPTS Sample

NPTS is designed to produce national and regional statistics about daily travel and the characteristics of the travelers, their households, and vehicles.  Except for states and metropolitan areas that purchased additional samples, NPTS sample sizes are not designed to provide reliable data at levels of the state or urban area.

Hence, the data should be used generally only to develop national or multi-state regional statistics, which is consistent with the design of the survey and the sampling procedures.

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