Citation

Sayers M, Gillespie TD. Transp. Res. Rec. 1981; 836: 29-35.

Copyright

(Copyright © 1981, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

Road meter systems that measure vehicle response to pavement roughness have limited accuracy, but more importantly, cannot be calibrated validly for use on all types of roads without access to a General Motors Research Laboratory-type profilometer. Even with good practice on the part of the users that eliminates the obvious effects of varied tire pressure, cargo weight, faulty components, and the like, limitations inherent to the road meter system remain. These limitations are due to the unique dynamic properties of each vehicle, the nonlinearities inherent to the vehicles and road meter instruments, and nonuniformities of the tire and wheel assemblies. This paper explores various improvements to road meters that will reduce the required calibration effort. The major source of nonlinearities in the vehicle-road meter systems are due to the road meter instruments and can be eliminated by the use of an equivalent electronic meter based on a linear transducer. With linear meters, it becomes possible to measure and correct for vehicle motions caused by tire and wheel nonuniformities. This can be done in the laboratory on a smooth drum roller or by special processing of on-road measurements keyed to wheel rotation as detected by an inductive pickup. However, even then, reference road-type surfaces are still required for calibration to scale the vehicle dynamic response. Only by the addition of accelerometers is it possible to compensate for vehicle dynamic response by simpler means of calibration. With this level of instrumentation, the road profile can be roughly determined and the road meter system has become a crude profilometer.