How does the FHWA compute VMT for a missing State in the TVT report?
In the event that a State does not have a traffic counter on a given functional classification of roadway, the TVT procedure is to estimate the missing value(s) from other functional classes from the same State. If the State does not have any valid values, the average value from the surrounding States for the same roadway functional class is used. If no surrounding State/States data are available, National average(s) are used.