Master Plan of Arterial Highways (MPAH)
Overview
OCTA administers the Master Plan of Arterial Highways (MPAH), including the review and approval of amendments requested by local agencies. The MPAH is a countywide transportation plan for Orange County, designed to manage and improve the arterial highway network. Established in 1956, the MPAH was created to complement the county’s developing freeway system and has evolved into a critical element of Orange County’s long-range transportation policy.
Over the years, the MPAH has played a crucial role in shaping the county’s transportation infrastructure, ensuring a coordinated effort between OCTA and the cities within Orange County. The primary goal of the MPAH is to outline a regional arterial highway system that supports existing and future land uses, ensuring that roads are designed to accommodate projected traffic volumes. It aims to provide a circulation system that complements the county’s freeway network, focusing on the efficient movement of people and goods.