Design & Construction Specifications - Town of Kernersville

Design CriteriaRoadway Design TableRes.StreetResidentialCul-De-SacStreetCollector /Sub-Col.Street 1MarginalAccessStreet 2IndustrialStreetIndustrial CommercialCul-De- Street 3Sac StreetROW width (ft) 50 50 60 / 50 30 - 60 60 50 45/50Min. Cul-de-Sac ROW Radius(ft)Min. Cul-De-Sac Radius F-F orV-V (ft)N/A 55 N/A N/A N/A 60 N/AN/A 45 N/A N/A N/A 50 N/AUtility Easement - Each Side (ft) 10 5 5 / 10 5 - 10 5 10 5Street Width F-F or V-V (ft) 28 4 26 37 - 40 /30 - 3726 - 40 40 37 37Min. Design Speed (mph) 30 25 35 / 30 25 - 40 40 30 35Min. Center Line Radius withnormal crown => normal crown(2%)225 150 400 / 250 225- 400 400 300 250Max. Grade (%) 5 10 10 7 7 7 7 7Min. Grade (%) 1 1 1 1 1 1 1Aggregate Base Course (in.) 8 8 8 8 - 10 10 10 8H-Binder or Approved alternate 2 2 3 / 2 2 - 5 6 4 6 3 2-3I-2 or I-1 Surface Course 1.5 1.5 1.5 1.5 2 2 1.5Tangent Length in ReverseCurves (ft)Min. Tangent Length atIntersectionAllowable Storm Water Spreadto Centerline of Street.30 10 50 / 40 50 100 100 3030 7 20 7 60 / 40 40 100 60 301/3 1/3 1/3 1/3 1/3 1/3 1/31) The Town shall determine collector classification.2) The Public Works Director shall determine the required street section and ROW width (seedetailed drawings) based on the maintenance and utility requirements to serve the adjacentdevelopment (s).3) Commercial Cul-de-sacs shall use the same design as Commercial Street w/ 175 radius.4) When residential streets intersect with thoroughfares, the street width shall be widened to a min.of 36’ starting @ the point of tangency with the intersecting radius for a distance of 60’, thentapering back to the street width as outlined above.5) Grades for 60’ each way from an intersection should not exceed 4%; however, steeper grades forthe first 60’ may be considered in extenuating circumstances for residential streets intersectingother residential streets.6) For streets in heavy industrial areas and other areas where the estimated ADT and estimatedpercentage of trucks is high, the Public Works Director shall determine the required amount of H-Binder based on an 18-kip EAL design.7) Tangent length shall be a minimum of 40-feet when approaching a collector or greater streetclassification.