LARIMER COUNTY RURAL AREA ROAD STANDARDS

Chapter 4 – Road Design and Technical CriteriaSection 4.5 Medians2This assumes the gravel on the Mainline County road is chemically treated. In instanceswhere the gravel road is not chemically treated, the paving threshold is 200 rather than400.E. Graveled roads, where permitted, shall be surfaced with a minimum of four inches ofClass 5 aggregate base course (ABC) or other material acceptable to the Engineer.The gravel shall be installed on a suitable subgrade. Prior to placing the gravel thesubgrade shall be reconditioned. This will include at a minimum scarifying the top 6”,wetting or drying as necessary and recompacting the subgrade. Once this iscomplete the material must pass a proof roll prior to placement of the gravel material.For gravel roads, the subgrade does not need to meet the testing requirements thatare necessary for a road paved with hot mix asphalt but must still pass a proof roll.4.4.1 Widening of Existing Paved RoadwayWhen widening an existing paved roadway for turn lanes, paved shoulders, additionallane width, etc, the Designer shall take into account that the asphalt joint for the widenedsections cannot be in a wheel path and must be designed to be either in the middle of atravel lane (joints in shoulders are not allowed) or on a lane line. Additionally the crossslope of the new widening must meet the requirements of Section 4.3.3.In order to accomplish the widening, the road may need to be sawcut at a lane line or inthe middle of a lane, or the entire area of the road adjacent to the widening may need tobe reconstructed or overlaid.If not overlaid, the roadway adjacent to widening and the widened portion may berequired to have a slurry seal or seal coat applied to provide a surface similar in textureand color as to not cause confusion to drivers.The Engineer will make the final determination of the method for the widening and thefinal surfacing treatment based on the adequacy of the existing roadway structure.4.5 MEDIANSRaised medians are not allowed unless approved by the Engineer at which time designstandards will be identified from the LCUASS.4.6 NON-CONNECTIVE ROAD ALIGNMENTS4.6.1 Construction Required as Part of ProjectAny roads within the development that are required to be designed to provide for futureconnectivity to adjacent properties must be constructed to the full applicable crosssection to the project boundary.4.6.2 Requirements for Future Road Projections1. The location of projected roads shall allow for the proper projection of thedrainage systems into adjacent existing, natural drainage areas.2. Stub Road: Where a road is indicated to dead end into an adjacent unplattedarea, the developer shall provide written approval from the adjacent landowner toLarimer County Rural Area Road Standards Page 4-6October 22, 2007