Highway Performance Monitoring System Field Manual

Appendix F. Metric-to-English Soft Conversion Procedures

The HPMS software requires the States’ data to be submitted in English units. States that maintain their data in metric units are required to apply a soft conversion factor to their data for HPMS submittal purposes. A soft conversion is a computation which involves the application of a conversion factor to an initial value for the purpose of producing a converted value. The converted value must then be rounded in accordance with the requirements for the specific data field or data item, as applicable.

Table F-1 provides a list of factors to be used when performing a Metric-to-English soft conversion:

Table F.1 Metric-to-English Conversion Factors

The following shows an example of how this procedure would be applied for the purpose of converting units of meters to feet:

3.9624 meters * (1 feet / 0.3048 meters) = 13 feet