LARIMER COUNTY RURAL AREA ROAD STANDARDS

Appendix F – Guidelines for Traffic Impact StudiesSection F.3 Level of Service, Access, Auxiliary Lane Requirements and Passenger Car EquivalentsE. Off-site roads where traffic from the proposed development or land use action willaccount for at least 20% of the average daily traffic upon build-out.F. Off-site intersections where traffic from the proposed development or land useaction:1. Contributes a 10% impact of the peak hour traffic on any approach leg of anintersection where the intersection is operating at a level of service C or betterupon build-out.2. Contributes a 5% impact of the peak hour traffic on any approach leg of anintersection where the intersection is operating at a level of service D or worseupon build-out.3. Impacts a specific turning movement that currently does not have an auxiliaryturn lane by at least 50% of the peak hour volume warrant for an auxiliary turn.F.3 LEVEL OF SERVICE, ACCESS, AUXILIARY LANE REQUIREMENTS ANDPASSENGER CAR EQUIVALENTSA. The acceptable level of service (LOS) (per the Highway Capacity Manual) for ruralroadways in unincorporated Larimer County (outside Larimer County adopted growthmanagement areas) is detailed in the Larimer County Land Use Code and is a LOSC.B. Access spacing is detailed in Chapter 10 of this document.C. Auxiliary lane warrants are included in Chapter 4 of this document.D. Unless specifically noted, all criteria in these standards are based on automobileoperations and performance. To allow for the impact of larger trucks, buses, andrecreational vehicles, “passenger car equivalents” shall be determined. A passengercar equivalent of 3 for each bus and all trucks and combinations of 40 feet in lengthor longer, or a passenger car equivalent of 2 for each vehicle or combination at orover 20 feet in length but less than 40 feet shall be used for these purposes.F.4 PAVING THRESHOLD STUDYF.4.1 When a Paving Threshold Study is RequiredThe County requires a Paving Threshold Study for any development proposal that willcreate more than two (2) new dwelling units or that is expected to generate more thantwenty (20) new daily vehicle trips on an unpaved or gravel road in the traffic impactarea.F.4.2 Paving Threshold Study RequirementsThe Paving Threshold Study must include at least the following information:1. A location map showing the development site, the boundaries of the traffic impactarea, and all roads, intersections, bridges or other roadway structures in thetraffic impact area.2. Identification of all unpaved or gravel roads in the traffic impact area and adetermination as to whether the gravel has been treated with chemicals for dustsuppression.Larimer County Rural Area Road Standards Page F-3October 22, 2007