Determining, improving and prolonging pavement friction in Illinois were the principal objectives in this five-phase study, which is summarized in this report. The friction tester developed and modified in Phase 1 measured the friction of pavements evaluated in the remaining phases. Phases 2 and 3 provided considerable insight into the pavement friction characteristics of existing interstate, primary, secondary, and local highways and have outlined geographical areas where a need for upgrading a particular type of pavement is greatest. Phase 4 demonstrated that satisfactory friction characteristics in bituminous sand mixes and in dense-graded bituminous concrete depend on the type, size, and amount of high-friction aggregate used in them, while Phase 5 reported information necessary to reduce wet-weather accidents. A list of published reports and their abstracts, emanating from this study, also is included. /FHWA/.
Samenvatting