Volume 2: Draft Gorst Planned Action Environmental Impact Statement

GORST PLANNED ACTION EIS | AFFECTED ENVIRONMENT, SIGNIFICANT IMPACTS, AND MITIGATION MEASURESLOS Roadways IntersectionsFSource: TRB 2000LOS StandardsCharacterizes arterial flow at extremely lowspeeds below one-third to one-quarter of thefree-flow speed. Intersection congestion islikely at critical signalized locations, withresultant high approach delays. Adverseprogression is frequently a contributor to thiscondition.Describes operations with control delay in excess of 80s/veh. This level, considered unacceptable to mostdrivers, often occurs with over saturation—that is,when arrival flow rates exceed the capacity of lanegroups. It may also occur at high V/C ratios with manyindividual cycle failures. Poor progression and longcycle lengths may also contribute significantly to highdelay levels.LOS standards are used to evaluate the transportation impacts of long-term growth and to ensure concurrency.Jurisdictions must adopt standards by which the minimum acceptable roadway operating conditions aredetermined and deficiencies may be identified.LOS standards for county arterials and state highways in Kitsap County involve three different policy approachesestablished by Kitsap County, and WSDOT. While somewhat diverse in application, all the standards andmethodologies are consistent with the Highway Capacity Manual (Transportation Research Board 2010) definitionsand procedures.County Roadways Kitsap County’s LOS policy generally recognizes that urban areas are likely to have morecongestion than rural areas. This reflects the different characteristics of land use and transportation in these areas.For purposes of defining LOS standards, all roadways within the Gorst UGA are considered urban.In rural areas, the system of major roads must have sufficient access to the abutting land uses, but because of thelow level of land development, rural roads have small capacity requirements. In contrast, urban areas typicallyattract and generate high volumes of traffic. In order to facilitate through traffic and minimize congestion, majorroads may have limited access to adjacent land uses while the more minor roads serve as access points to thesurrounding development. The increased density and activity in an urban area inherently results in higher levels ofcongestion. Drivers are aware of the differences in land use between urban and non-urban areas and generally aremore tolerant of congestion and the associated lower LOS in urban areas than in rural areas.The LOS standards shown in Table 3.11-3 Roadway Capacity/Congestion LOS Standards are based on the locationand functional classification of the roadway facilities to which they apply. Kitsap County uses traditionalengineering methodology to evaluate LOS of roadway segments, which are sections of roadway located betweenmajor intersections. LOS is based on the Volume-to-Capacity Ratio (V/C), which is calculated by dividing the trafficvolume on a roadway by the roadway’s vehicle capacity. LOS methodologies are described in further detail in theMethodology section of this chapter.Draft | June 2013 3-156