The objectives of the study were to review and modify previously used Equivalent Single Axleload (ESAL) prediction procedures and to develop a more efficient procedure. As part of the effort to simplify the procedure, a subtask was undertaken to reduce the number of highway functional classes being used to process data for the ESAL estimation procedure. Another objective was to develop a more definitive and accurate method for reflecting the effects of coal or heavy truck movements. Results of this task were documented as Research Report KTC-95-6.

Analyses were performed and validated to reduce the twelve functional classes to six aggregate categories. The overall ESAL estimating process, which was previously accomplished using mainframe computer programs, was converted to microcomputer/PC programs and documented in detail. A procedure for processing ESAL data by aggregate classes was documented and example output was presented. An analysis was performed to determine the reliability of traffic parameter estimates used in the ESAL estimating process. Results were produced to identify the number of volume, classification and weigh-in-motion stations required to adequately define the traffic characteristics of a specific functional or aggregate class.

Report Date


Report Number


Digital Object Identifier



Revised December 1995

The contents of this report reflect the views of the authors who are responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the University of Kentucky, the Kentucky Transportation Cabinet, or the Federal Highway Administration. This report does not constitute an standard, specification, or regulation. The inclusion of manufacturer names or trade names are for identification purposes and are not considered as endorsements.