The primary mission of the California Highway Patrol is "the management and regulation of traffic to achieve safe, lawful, and efficient use of the highway transportation system." As a major statewide law enforcement agency, the secondary mission of the Department is to assist in emergencies exceeding local capabilities. The CHP also provides disaster and lifesaving assistance.

During its first ten years, the Patrol successfully grew into a highly respected, effective traffic safety force of 730 uniformed personnel. After World War II, the legislature decided to consolidate and reorganize the Patrol's enforcement and administrative responsibilities. In October 1947, the Department of the California Highway Patrol was established and the position of commissioner was created to head the new Department.

The span of enforcement responsibility has expanded dramatically and the CHP has continued to grow and change. Today's responsibilities include truck and bus inspections, air operations (both airplanes and helicopters) and vehicle theft investigation and prevention. The 1995 merger with the California State Police also increased the areas of responsibility to include protection of state property and employees, the Governor and other dignitaries.

In addition to its enforcement responsibilities, the Department has taken a leadership role in educating the public concerning driver safety issues. The CHP has received state and national recognition for its innovative public awareness campaigns promoting use of safety belts, a Designated Driver when drinking, securing small children in safety seats and wearing motorcycle and bicycle helmets.