SR-55 is major north-south freeway corridor in Orange County, extending from the 19th St. intersection to the SR-91 interchange. Within the study corridor, there are a number of major freeway-to-freeway system interchanges, including SR-73, I-405, I-5, SR-91 and SR-22. The corridor has three to five mixed-flow lanes and one HOV lane with full-time continuous access along most sections. The corridor primarily consists of commuter traffic, and therefore, typical weekday morning and afternoon peak periods are of concern.