EVENNESS. THE CHARACTERIZATION OF THE SURFACE CONDITIONS OF ROADS

THE PROPERTIES OF A CARRIAGEWAY SURFACE ARE DESCRIBED MAINLY BY THE SKIDDING RESISTANCE, EVENNESS INCLUDING INCLINATION, DRAINAGE ABILITY AND REFLECTION BEHAVIOUR. EVENNESS IS DIFFICULT TO DEFINE FOR PRACTICAL CONDITIONS. WHEN CONSIDERING EVENNESS DIFFERENTIATION IS MADE BETWEEN: THE EVENNESS ITSELF, THE AND RIDING COMFORT. IS A FUNCTION OF TRANSFORMATION WHICH IS REPRESENTED BY SURFACE CONDITIONS WHICH CAN BE MEASURED BY HUMAN PERCEPTION RELATIVE TO THE ROAD. RIDING COMFORT IS A FUNCTION RELATED TO THE VEHICLE. THE RIDEABILITY ACCORDING TO AASHO CAN BE USED FOR DESCRIBING THE CONDITION OF A ROAD. BASED ON MEASUREMENTS ON 400 SECTIONS OF ROAD AND ON EXPERIMENTAL STRETCHES ON THE GERMAN FEDERAL MOTORWAY (BAB) FROM MUNICH TO NUERNBERG THE FOLLOWING FACTS WERE ESTABLISHED: THE IS THE BEST AND UNIVERSALLY USED MEASUREMENT OF SURFACE EVENNESS. THE SUBSEQUENT BEHAVIOUR OF A ROAD IS VERY MUCH INFLUENCED BY ITS CONDITION WHEN NEW. MEASUREMENTS ON ROADS LEAD TO THE ASSUMPTION THAT THE EQUIVALENT AXLE LOAD FACTORS DEVELOPED IN THE AASHO ROAD TEST ARE NOT RELIABLE AS GIVEN THERE IN SIMPLE FORM.