EXPERIENCE WITH A BPR-TYPE ROADOMETER IN ILLINOIS

THE ILLINOIS DIVISION OF HIGHWAYS IN 1957 CONSTRUCTED A ROAD ROUGHNESS INDICATOR (ROADOMETER) PATTERNED AFTER THE DEVICE INTRODUCED BY THE BUREAU OF PUBLIC ROADS IN 1941. NUMEROUS MODIFICATIONS WERE MADE IN ADAPTING THE DEVICE FOR USE IN ILLINOIS. AFTER AN EXTENSIVE SERIES OF TESTS, THE ILLINOIS INSTRUMENT WAS PLACED IN REGULAR SERVICE RECORDING THE SMOOTHNESS OF NEW AND OLD PAVEMENTS BEGINNING IN 1959. THE RECENTLY DEVELOPED USE OF ROAD ROUGHNESS INDICATORS IN FURNISHING MEASUREMENTS THAT ASSIST IN ESTIMATING THE PRESENT SERVICEABILITY OF PAVEMENT UNDER THE CONCEPT ORIGINATING AT THE AASHO ROAD TEST HAS GREATLY ENHANCED THE VALUE OF THESE DEVICES. VARIOUS MODIFICATIONS MADE BY ILLINOIS ARE DESCRIBED IN CONSTRUCTING ITS ROADOMETER AS WELL AS THE TESTS IN WHICH IT HAS BEEN SUBJECTED AND ITS USE IN RATING ILLINOIS PAVEMENTS UNDER THE PRESENT SERVICEABILITY CONCEPT FOLLOWING CORRELATION OF THE DEVICE WITH THE AASHO ROAD TEST PROFILOMETER. /AUTHOR/