Citation

Maeda Y. Transp. Res. Rec. 1977; 621: 67-74.

Copyright

(Copyright © 1977, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

As in many other countries, many traction measuring methods have been used in Japan. For example, there are such methods as measuring stopping distance, deceleration of a car when braking force is applied, braking force or torque obtained by a instrumented towed trailer or a vehicle with wheel etc. for measuring braking traction. For measuring cornering traction, we have maximum speed at which a tethered or non-tethered car being driven in a circle at increasing speed loses control, the relation between cornering or lateral force and slip angle obtained by a towed trailer or a vehicle with a fifth wheel etc. Several indoor testing methods are also used. Since tire-road traction mechanisms of cars driven on public roads are very complicated, one must consider the purpose in measuring such traction. On case may be to evaluate whether the tires are suitable for the market. Another may be to research tire traction problem. It is difficult to measure all the characteristics of tire traction with any one measuring method and a suitable method or methods for the purpose should be selected. In addition, the subjective feeling of the driver should be considered as to the ease of driving control, because cars are driven by human beings. This paper introduces tire-road traction measuring methods used in Japan and discusses their advantages and disadvantages from the previously mentioned standpoints. It also report on a newly developed tire traction testing vehicle along with several typical test results.