TRR No. 1260 Pavement Design, Management And Performance, pp. 112-124
Highway engineers have always been concerned with providing pavements of acceptable serviceability. The serviceability of a highway segment, which is largerly a function of pavement roughness, is a widely used criterion for deciding when pavements are in need of rehabilitation. For this application, various statistics are currently used as indicators of pavement serviceability, the most common being the present serviceability index. This statistics are largerly determined from measurements of pavement roughness. Various devices and procedures have benn developed for accomplishing these measurements. Of practical necessity, devices for measuring pavement roughness must be capable of providing repeatable measurements at normal highway speeds. In addition, that possess the capability for field processing of the data collected, and that are relatively inexpensive to own, operate, and maintain are most desirable. The Siometer, which is currently used by the Texas State Departement of Highways and Public Transportation (SDHPT) for evaluation of pavement riding quality, holds promise as an instrument for the routine collection of profile data on a network-wide scale. The Texas SDHPT has recently begun investigating the profile-measuring capability of the Siometer. A unique feature of this device is the statistical modeling procedure for characterizing the vehicle on which it is installed, which lends portability to the Siometer. In it, the parameters of the stastical model are determined in a self-calibration procedure that is run before profile data are collected. To evaluate the applicability of the Siometer as a device for profile measurements, profile measurements with the Siometer were compared with those from a profilemeter.