Surface DrainageCrown (flat A shape)Dirt & Gravel: 1/2 - 3/4 per foot(4 - 6 inches in 10 feet)

Surface DrainageSuperelevated Roadway (Curves)Dirt & Gravel: 1/2 - 3/4 min. per foot

Surface Drainage - ShouldersFlush with roadAvoid shoulder drop offSlightly steeper cross slopeAvoid secondary ditchesSupports roadwayAllows water to flow further away from road

Drainage SystemsWrongRightCrownSurface MaterialDitchShoulderSubgradeBaseSurface MaterialSubgradeBase

Subsurface DrainageFree draining road base beneath the surfaceCollector systems comprised of perforated pipe surrounded by well-graded aggregate with an outlet pipe or other prefabricated systems

SubdrainsRoadShoulderSubdrainWell-graded aggregatePerforated PipeCut or Fill Sections

3 Most Important Items in Road MaintenanceDrainageDrainageDrainage

Road MaterialsDurability (Hardness)SoundnesspH (acidity/alkalinity)

Road AggregatesGranularWell Graded (8 15% fines)Free of VegetationAngular / Irregular (Source)CrushedNot rounded

Basic Road MaintenanceCreate a good hard crust surface with a proper cross slope (crown)

Basic Road MaintenanceBlading or smoothingGrading or reshapingAdding new materialTransitions

Basic Road MaintenanceAll work should be done when some moisture is presentNeed moisture for proper compactionAvoids dust

Blading or SmoothingUse grader or dragMold board tilted forwardLight down pressure30 to 45 degree angle on moldboard10 to 15 degree tilt on front wheels3 to 5 miles an hour

Grading or ReshapingMoldboard tilted backwardSufficient down pressure to produce cutting action4 passes minimumWindrow & spread each laneCheck cross slopeCompact

Adding New MaterialScarify existing surfaceSpread new materialBlend old and new material & establish cross slopeCompact

TransitionsRoad IntersectionsDrivewaysCurvesRailroad CrossingsBridges

Road IntersectionsGradually eliminate crown 50 to 100 feet from intersectionBe sure shoulders have cross slope at point of intersectionDo not spread aggregate on paved road

DrivewaysGrade to drivewayGrade low point at ditchlineDo not leave windrow across driveway

CurvesTransition crown to superelevation (and vice versa) within 100 feet of curves10050250

Railroad CrossingsGradually eliminate crown on both sidesDo not blade aggregate onto railsBrush off loose aggregate

BridgesIf bridge has crown, maintain on roadIf not, gradually eliminate crownRoad approaches to bridge may need more frequent attention

Maintenance FrequencyDepends on:Road TypeDrainageWeatherTraffic VolumesSpecial Events

As Needed!

The Professional OperatorKnows good techniques & practicesKnows his equipmentNotices and records other problems that need to be taken care of