Verification of rut depth collected with the INO laser rut measurement system (LRMS) : executive summary report

Executive summary report.PDFTech ReportFHWA/OH-2011/18SJN: 134515RuttingMechanistic designPavement performancePavingLaser beamsRatingsPerformance measurementPerformance testsOhioOhio. Dept. of Transportation. Innovation, Research, and Implementation SectionHoffman, Bradley R.Sargand, Shad M.Ohio. Dept. of TransportationOhio. Dept. of Transportation. Innovation, Research, and Implementation SectionNTL-HIGHWAY/ROAD TRANSPORTATION-Pavement Management and PerformanceNTL-HIGHWAY/ROAD TRANSPORTATION-DesignNTL-HIGHWAY/ROAD TRANSPORTATION-Construction and MaintenanceUS Transportation CollectionSince 1985, ODOT has been manually collecting rutdepth data using a straight edge and dial gauge (S&G). Thismethod is slow and dangerous to pavement condition raterswhen traffic control is not available. According to thePavement Condition Rating (PCR) procedures, the ratingteam is instructed to stop at 1 mile intervals along thepredetermined roadway section and evaluate a 100 ft (30.5 m)section of pavement. While this method may be sufficient inmany cases, there is potential for raters to overlook shortsections of deeper than typical rutting. Also, there have beennumerous instances, according to ODOT InfrastructureManagement workers, when the level of traffic preventedthem from obtaining the necessary number of rut depthmeasurements to properly evaluate a pavement section. Tosolve this problem, ODOT purchased two inertial roadprofilers; one from Pathway Services and one from Dynatest.Both vehicles use rear-mounted INO Laser Rut MeasurementSystems (LRMS). These systems utilize two 3D laserprofilers and allow the collection of transverse road profilesand calculation of rut depth measurements while the vehicleis in motion, even at high speeds. With the LRMS, numerousrut measurements can be obtained at short intervals over theentire section in a much shorter period of time. The safetyrisk for the rating team is greatly reduced because they canobtain measurements without leaving the vehicle and withoutinterfering with traffic flow