California's transportation system is one of the largest and most complex in the country, but faces funding challenges to maintain and expand its infrastructure. Public-private partnerships (P3s) are being explored as a way to leverage private funding to help address an estimated $80-150 billion funding gap. California has pursued some P3 highway projects in the past, and currently has several prospective P3 projects in development that could provide billions of dollars in additional transportation infrastructure investment. However, P3 projects also present challenges around ensuring transparency, appropriate risk allocation, and managing public perceptions.