The Analysis and Determination of Tire-Roadway Frictional Drag 2003-01-0887
Tire-roadway frictional drag, an important consideration for transportation accident reconstruction, is dependant on vehicle, roadway and environmental factors. Vehicle factors include vehicle specific properties such as geometry and inertial parameters, braking system type, tire size, and tire properties. Roadway factors include grade, pavement type, construction, pavement age, and other parameters. Environmental factors include temperature and inclement weather.
In order to control these (and other) vehicle, roadway, and environmental factors, the determination of tire-roadway frictional drag is done through staged testing using an instrumented vehicle. Staged testing is typically performed with an exemplar vehicle on a similar roadway under comparable environmental conditions. Engineering instrumentation includes acceleration and velocity sensors as well as a brake gun to directly measure total braking distance.
The paper describes the utilization and application of full scale testing to determine tire-road friction under locked wheel braking on asphalt roadways. Instrumentation factors, including sampling rate, sensor accuracy, and sensor type are discussed. Analysis methodologies, including direct and indirect determination of test parameters, are explored. The testing was done on roadways of known paving date. Therefore, the effects of pavement factors such as age and construction on the determination of tire-roadway frictional drag are studied.