1992 CENSUS OF TRANSPORTATION
1992 TRUCK INVENTORY AND USE SURVEY


ABBREVIATIONS AND SYMBOLS  

The following abbreviations and symbols are used in this publication:  

N    Not available due to new data item or definitional differences.

S    Withheld because estimate did not meet publication standards on the
     basis of either the response rate, associated standard error, or a
     consistency review.  

Z    Represents less than 50 trucks or .05 percent, as appropriate for
     the data column.  

RSE  Relative standard error.