In order to improve the utility of HPMS, the Highway Performance Analysis Branch (HPN-21) has reviewed the HPMS data base and the Analytical Process. The purpose of this review was to determine the sensitivity of the HPMS Analytical Process to the input data and to the minimum tolerable conditions (MTC) used as threshold levels to identify deficiencies, The three principal areas of review were as follows: 1. Determine the characteristics of the data, i.e., what values are coded for specific data items, Besides providing "nice-to-know" information about the coding practices, this information provided input to part 2 of the review. The results were used in determining which data elements would be reviewed in the sensitivity analysis, 2. Determine the sensitivity of the Analytical Process to changes in certain coded data items, e.g,, what happens to the results of the Analytical Process if traffic growth is different than coded, or if the percent trucks is different. 3, Determine the sensitivity of the model to changes in the MTCs, e.g,, using the current national default MTCs as a benchmark, what happens to the results of the Analytical Process if we are willing to accept a higher level of congestion before adding lanes, or to accept narrower lanes. This report contains the results of Parts 2 and 3 of the project. The results of Part 1 are contained in a companion volume dated May 1987.

US Transportation Collection
Federal Highway Administration