The California Highway Patrol (CHP) is the principal state police agency for the U.S. state of California. The CHP has primary jurisdiction, including patrol and investigations, over all California freeways and state property. Additionally, the CHP is responsible for the enforcement of all laws regulating the operation of vehicles on highways, including all roadways, outside incorporated city limits. The CHP can exercise law enforcement powers anywhere within the state.
https://en.wikipedia.org/wiki/California_Highway_Patrol