This document provides an overview of public-private partnerships (P3s) for transportation projects in California. It notes that California has one of the largest transportation systems in the country but faces major funding shortfalls to maintain and improve it. It outlines legislation allowing P3s and Caltrans' goals to integrate P3s as a sustainable project delivery method. Several potential P3 "pipeline projects" are described, including improvements to highways in Los Angeles and the Presidio Parkway project in San Francisco. Challenges of valuing P3s and transferring appropriate risk are also discussed.