Citation

Kawato H, Oyu H, Sasaki S. Jpn. J. Forensic Sci. Tech. 2015; 20(1): 51-58.

Vernacular Title

冬季路面における摩擦係数の測定

Copyright

(Copyright © 2015, Japanese Association of Forensic Science and Technology)

DOI

10.3408/jafst.680

PMID

unavailable

Abstract

The purpose of this research is to measure coefficient of friction of the road surface in the winter season that varies on temperature, snow compression, snow coverage and other factors. In the winter, road conditions change over time, the fresh snow on the road surface changes to compacted snow, slush, melts and becomes water by the rising temperatures and the passage of the vehicle. It is possible to obtain an accurate velocity by using coefficient of friction according to the road conditions.   

Therefore, this research measured coefficient of friction of the road surface conditions of fresh snow, compacted snow, and slush as can be predicted on the winter road surface. For example, with usual slush that can be seen when there is little snow and heavy traffic, the coefficient of friction of the state of slush is 0.35-0.40, the state of melting slush is 0.40, the state of almost melted and water is 0.54. It is necessary to use the appropriate coefficient of friction depending on the road conditions for the same slush.  

In addition, this research measured the coefficient of friction from a vehicle that side slipped and stopped on a slope in compacted snow. From the results of measurement, the coefficient of friction from a side slipped vehicle stopping on a slope in winter road surface with compacted snow was not observed as much as the coefficient of friction of side slipped and braking experiments. The numerical value of the coefficient of friction when a vehicle is stopped at a traffic light could be considered for future reference.