On August 14, 1929, the California Highway Patrol was created. The new law gave Statewide authority to the Highway Patrol to enforce traffic laws on county and State highways — a responsibility which remains in effect today. 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.

License Plates of the California Highway Patrol

Prior to the formation of the California Highway Patrol in 1929, state traffic law enforcement was handled by Inspectors of the California Motor Vehicle Department. From 1917 to 1921, these patrol officers were assigned the task of enforcing highway traffic conduct and equipment laws in the Golden State. A snag occurred with a 1923 court ruling which decreed that county traffic officers could not enforce state traffic laws. This necessitated state-appointed traffic officers for each county in California, but supervised by DMV Inspectors and Deputy Inspectors who were not restricted by county lines.

There is no clear photographic evidence or written record that clarifies what type of plates the California Motor Vehicle Department Inspectors ran on their cars at the time. There is, however a 1923 promotional photo for a wheel-siren company that shows a "bathing beauty" wearing a California MVD Inspector's hat, badge and riding gloves standing next to a patrol motorcycle bearing a 1923 state exempt (Diamond E) motorcycle license plate # 39. Therefore it can be surmised that MVD Inspectors ran California State Exempt license plates on their patrol cars as well at that time.

California has perhaps had the longest and most consistent formatting of such state vehicle identifiers anywhere in the U.S. as the "Diamond E" plates were run for over 80 years on state vehicles including those of the California Highway Patrol from 1916 until 1997.

These plates emulated the color and format of regular state passenger license plates of the given years. They have also been consistently run front-and-rear since the beginning.

The earliest versions were porcelain enameled steel plates measuring 4.5" x 13". The colors were blue characters over a white background. Four mounting holes were provided lined with brass grommets to prevent chipping of the porcelain when fastened to the vehicle. A year tab was affixed above the abbreviation CAL along the left margin of the plate, followed by the <E>and a number up to 4 digits. The years for the plates from 1916 to 1919 were validated by tab attachments with the corresponding registration number engraved upon the device made of the following designs/ material:
1916: Walking bear profile made of lead (# <E> 316, 635 and 2768 confirmed for 1916)
1917: A yellow painted embossed lead poppy
1918: A green painted embossed lead mission bell
1919: A red painted metal embossed star

1956 saw the experimentation of a new technology in the state to make license plates more visible in low-light conditions. Crushed glass bead material was added to the surface paint of the galvanized steel license plates and used to test the reflective properties of the background of the plate as a measure for added traffic safety. CHP patrol vehicles were chosen for this experiment as these vehicles had the most continuous exposure to the elements and other wear-and-tear than any other state vehicle in the fleet.
The experiment must not have been too successful as California did not opt for reflective license plates until 26 years later!
Later versions of the 1956-1963 plate used flat painted backgrounds and were made of aluminum with a registration number using six numbers.

This is how to visually differentiate between the older steel version and the later aluminum version of the 1969-1982 "blue plates". The steel version has a much "tighter" state name while the aluminum version is more spread-out.

Motorcycle License Plates used by California Highway Patrol

As with the "car sized" plates of the California Highway Patrol, motorcycle plates of the CHP were based on the same color and formatting as regular motorcycle license plates issued by the state with the exception of the <E> prefix for a state exempt motor vehicle. Again, if we are to surmise that California DMV Inspectors, the "pre-CHP" officers used state exempt plates on their motorcycles since the beginning, the following specimen types would have been used:

The earliest versions were porcelain enamelled steel plates measuring 3" x 10" and in a curved or concave format to fit over the rear fender of the motorcycle. Two mounting holes were provided with one at the top and one at the bottom of the plate. CAL was inscribed horizontally across the top of the plate over the <E> followed by a number and over two more numbers. The years for the plates from 1916 to 1919 were validated by tab attachments with the corresponding registration number engraved upon the device made of the following designs/ material:

1916: Walking bear profile made of lead
1917: A yellow painted embossed tin poppy
1918: A green painted embossed tin mission bell
1919: A red painted metal embossed star

California motorcycle license plates sported six mounting holes from 1920 until 1970.

Specialty Issues

These are a few specialty issues not for sanctioned use on duty.