State Route 55 Highway Capacity Analysis, Orange County, California
KOA conducted an analysis of traffic conditions along State Route 55 in Orange County from State Route 91 to 19th Street in Costa Mesa, California. The analysis of traffic conditions and queuing considered the northbound and southbound directions during AM and PM peak periods and showed how congestion builds on the facility during peak periods and persists beyond the traditional end of the peak. The study utilized a Highway Capacity Manual based tool called FREQ (Freeway Corridor Simulation and Ramp Metering Optimization Model) that permitted efficient analysis of the corridor, including hotspots, bottlenecks and geometric features. A travel time / speed survey was used to calibrate the models. The goal was to recommend the most cost-effective congestion relief improvements for the freeway, such as adding auxiliary lanes at bottlenecks.