Deriving California-Type Profilograph Outputs from Rsp Roughness Measurements

The roughness specifications of a recent Israeli PWD concrete road project, consisting of a 4-lanes stretch of a 7- kilometer length (Route No.3), included both bonuses and penalties in their pay-adjustment functions. The California-type profilograph outputs served as the data for these functions. The reason for using this particular profile measuring device stemmed from the rich experience acquired with it across the U.S. and Canada. However, ongoing progress in this area calls for the use of modern machines, which are equipped with laser optical distance measurement devices (laser sensors) and accelerometers. Thus, a Road Surface Profiler (RSP) was utilized for the roughness measurements in the aforementioned concrete road. This machine is capable of measuring, calculating in real-time, displaying, and storing on a computer hard disk longitudinal road profiles and roughness data in terms of IRI (International Roughness Index). Thus, the output of this machine also enables virtual runs of the California-type profilograph on the measured longitudinal road profiles. The complete method and its relevant equations are shown in the paper. Finally, the paper includes statistical studies in order to compare the IRI outputs as obtained from the RSP machine measurements with the PI outputs as obtained from the virtual runs of the California-type profilograph. Significant correlations were, thus enabling the PI requirements to be replaced with the compatible IRI outputs. Tentative recommendations on this matter are given.