Floyd County Thoroughfare Plan - Floyd County Indiana - State of ...

Floyd County, IndianaFloyd County Thoroughfare PlanSection 2–Needs Identification2.03 EXISTING MOTOR VEHICLE OPERATIONS ANALYSISMotor vehicle operations were analyzed using two methodologies. First, for portions of the studyarea where there is a lack of intersections identified as warranting detailed analysis, overallcorridor operations were analyzed using the Highway Capacity Software (HCS) Two-Lane module.This method of analysis considers lane and shoulder width, highway classification, traffic volumes,directionality of traffic, traffic speed, type of terrain (level or rolling), percent no-passing zones,access point density, and vehicle classification (percent heavy vehicles and percent recreationalvehicles). The highway is evaluated based on a Level of Service (LOS). Along a Class I two-lanehighway the LOS rating is based on percent time-spent-following and average travel speed. Alonga Class II two-lane highway, where mobility is less critical, the LOS rating is based on percenttime-spent-following only. The roadways studied in Floyd County are Class II highways. The LOSratings range from LOS A (ideal conditions) to LOS F (volume exceeds the highway’s capacity).LOS A indicates that the average vehicle travels at the highway’s ideal free-flow speed. LOS Findicates that traffic volumes exceed the highway’s theoretical capacity and major delays andsafety concerns can be expected.Within the study areas where intersections identified for detailed analysis are more closelyspaced, the study team used Synchro/SimTraffic software. SimTraffic uses microsimulation, whichmodels individual vehicles on a simulated network that represents existing or proposed streetconditions. Operations using this type of analysis are evaluated based on conditions at theintersections. LOS is based on average delay in seconds per vehicle for traffic entering theintersection. LOS A indicates that travelers will experience minimal average delay at anintersection (less than 10 seconds). LOS F indicates that the average delay is quite high (morethan 50 seconds at an unsignalized intersection and 80 seconds at a signalized intersection).Table 2.03-1 shows the delay thresholds for LOS at signalized and unsignalized intersections.Level Of ServiceSignalized Intersections(average delay, seconds)Unsignalized Intersections(average delay, seconds)A < 10 < 10B 10 to 20 10 to 15C >20 to 35 >15 to 25D >35 to 55 >25 to 35E >55 to 80 >35 to 50F > 80 > 50Table 2.03-1 Level of Service (LOS) ThresholdsLOS E is often considered to be the limit of acceptable delay and LOS F indicates a facility onwhich improvements are needed. Floyd County has established LOS D as their minimumacceptable level of service.Prepared by Strand Associates, Inc. ® 2-5KRH:pll\S:\@SIECO\001--050\046\008\Wrd\Thoroughfare Plan\Draft 07-19-07\S2-Needs Identification 07-19-07.doc\072007