Data Collection for Determining Pavement
ConditionFrictionProfileRut DepthStructureDistress
identification
Friction DeterminationImportanceInadequate friction leads to
higher number of crashesRequired to provide a safe roadCan be used
to evaluate materials-AWIEvaluated asLocked WheelSpin Up
TestSurface Texture Measurement
Friction-Locked WheelASTM 261Standard TireWater on surface40
MPH
Friction tester- Locked Wheel
Friction TesterSpin upWheel Lowered at 40 MPHFriction
force=torque/tire radiusf= Friction Force / WeightBetter then
Locked Wheel as less equipment is required
Spin Up Friction Tester
Road Surface AnalyzerA laser-based profiler using an
accelerometerestablished inertial reference.ROSAN measures texture
and longitudinal pavement profile at highway speeds.Texture
Analysis - Determination of Mean ProfileDepth Smoothness Analysis -
Roughness Analysis - Determination of InternationalRoughness Index
(IRI) & Ride Number (RN), usingASTM E 950 & E 1926
Road Surface Analyzer
Roughness Measuring
Rod and LevelDipstick profilerRoad roughness MeterProfiling
Devices
Roughness MeasurementPresent Serviceability Rating (PSR)Based on
ride quality defined by observerValues from 1-5International
Roughness IndexBased on Average Rectified Slope (ARS) determined
from vehicle accumulated suspension motion divided by the distance
m/kmIRI= 1000*ARS
Dipstick AnalyzerOperation The Dipstick Road Profiler stands on
two support legs. The operator simply "walks" the Dipstick along a
survey line alternately pivoting the instrument about each leg. Two
digital displays show the elevation difference between the
Dipstick's two support legs. Audible and visual signals alert the
operator when each elevation difference reading is measured and
automatically recorded.
