Annual Update of Data for Estimating ESALS -- State Highway Quick Response Study No. 42

A revised procedure for estimating equivalent single axleloads (ESALs) was developed in 1985. This procedure used weight, classification, and traffic volume data collected by the Transportation Cabinet's Division of Transportation Planning. The procedure was developed and documented as Research Report UKTRP-85-30, and was titled "Estimation of Equivalent Axleloads". Since the revised procedure was adopted, there have been several changes to the procedures; the most recent being documented as Report KTC-95-7 titled "Equivalent Single Axleload Computer Program Enhancements". Results documented in Report KTC-95- 7 included improvements in the processing ofESAL data by aggregation of the functional classes to increase the accuracy of the estimates within a class, and convert computer programs used to process the data from mainframe to personal computer. The most recent traffic characteristics data will be processed to produce estimates of the following parameters: Average daily traffic, Percent trucks, Percent trucks classified as heavy/coal, . Axles per truck, Axles per heavy/coal truck, ESALs per truck axle, ESALs per heavy/coal truck axle, and. Total ESALS. In addition, Report KTC-99-1 was prepared to document analysis methods used to prepare ESAL estimates for Superpave projects. The methodology included an interactive program which permitted users to access various data bases in order to calculate ESAL Superpave estimates. Work accomplished during 2002 year resulted in updating this interactive program for use with Superpave ESAL estimates. The objectives of the proposed activity will be to: 1) update the data used for estimating ESALs by processing weight, classification, and traffic volume data, and 2) address trends in weight data collection during the most recent three years which has produced values of ESAL's per truck axle that were significantly higher than previous years.