Citation

Close W. Highw. Res. Board bull. 1961; 302: 18-34.

Copyright

(Copyright © 1961, National Research Council (U.S.A.), Highway Research Board)

DOI

unavailable

PMID

unavailable

Abstract

The friction coefficient between a pair of locked automotive tires (running in the normal wheel tracks) and a wet highway surface was determined in an elaborate test program, using a specially constructed test trailer. This program provided data from more than 400 tested surfaces along approximately 6,500 route miles of rural sections of major transcontinental routes following the national system of interstate and defense highways as nearly as possible. The data are tabulated, and cross-plots have been made to indicate the effects of age, wear (based on age and traffic volume), surface finish and aggregate composition on the friction coefficient exhibited by portland cement concrete roads. Summaries are made also for the comparative effects of age and wear on the friction coefficients of pcc and bituminous asphalt roads.