ROAD ROUGHNESS MEASUREMENTS OF VIRGINIA PAVEMENTS

TESTS WERE CONDUCTED PRINCIPALLY ON HIGH-TYPE PAVEMENTS ON PRIMARY ROADS. PORTLAND CEMENT CONCRETE, BITUMINOUS CONCRETE, WATER-BOUND MACADAM, TRAFFIC-BOUND MACADAM AND PENETRATION MACADAM SURFACES WERE TESTED. PROJECTS TESTED VARIED FROM 0.94 TO 23 MILES IN LENGTH. TEST SECTIONS WERE SELECTED TO PERMIT AN EVALUATION OF THE RIDING QUALITIES OF THE DIFFERENT DESIGN CHARACTERISTICS OF THE FIVE TYPES OF SURFACE. TESTS WERE CONDUCTED ON TWO, THREE, AND FOUR-LANE PAVEMENTS WITH TRAFFIC COUNTS (24-HR. BASIS) RANGING FROM 94 TO 6566 VEHICLES. ROAD ROUGHNESS MEASUREMENTS RANGED FROM A MAXIMUM OF 272 FOR WATER-BOUND MACADAM TO A MINIMUM OF 62 FOR BITUMINOUS CONCRETE WITH AN AVERAGE OF 156 IN. PER MI. FOR ALL PROJECTS TESTED. THE AVERAGE FOR EACH TYPE RANGED AS FOLLOWS: BITUMINOUS CONCRETE 86, PORTLAND CEMENT CONCRETE 112, WATER-BOUND MACADAM 193 AND PENETRATION MACADAM 200 IN. PER MI. THERE WAS VERY LITTLE DIFFERENCE IN THE RIDING QUALITIES OF BELT-FINISHED AND BROOM-FINISHED PORTLAND CEMENT CONCRETE OR IN BITUMINOUS CONCRETE SURFACES HAVING A WIDE RANGE IN TEXTURE. HOWEVER, IN THE MACADAM SURFACES THE TESTURE OF THE SURFACE TREATMENT INFLUENCED THE RIDING QUALITIES OF THE PAVEMENT CONSIDERABLY. MIXED-IN-PLACE SURFACE TREATMENT PROVIDED A MUCH BETTER RIDING SURFACE THAN PLAIN SURFACE TREATMENT. THE ROAD ROUGHNESS INDICATOR WAS FOUND TO BE A QUICK, DEPENDABLE METHOD OF MEASURING RIDING QUALITIES OF PAVEMENT SURFACES. /AUTHOR/