Actually, there are jurisdictional boundaries in California, and they do limit the authority of city police officers and county sheriffs. Penal Code section 830.1 says:
"(a) Any sheriff, undersheriff, or deputy sheriff, employed in that capacity, of a county, any chief of police of a city or chief, director, or chief executive officer of a consolidated municipal public safety agency that performs police functions, any police officer, employed in that capacity and appointed by the chief of police or chief, director, or chief executive of a public safety agency, of a city, any chief of police, or police officer of a district, including police officers of the San Diego Unified Port District Harbor Police, authorized by statute to maintain a police department, any marshal or deputy marshal of a superior court or county, any port warden or port police officer of the Harbor Department of the City of Los Angeles, or any inspector or investigator employed in that capacity in the office of a district attorney, is a peace officer. The authority of these peace officers extends to any place in the state, as follows:
" (1) As to any public offense committed or which there is probable cause to believe has been committed within the political subdivision that employs the peace officer or in which the peace officer serves.
" (2) Where the peace officer has the prior consent of the chief of police or chief, director, or chief executive officer of a consolidated municipal public safety agency, or person authorized by him or her to give consent, if the place is within a city or of the sheriff, or person authorized by him or her to give consent, if the place is within a county.
" (3) As to any public offense committed or which there is probable cause to believe has been committed in the peace officer's presence, and with respect to which there is immediate danger to person or property, or of the escape of the perpetrator of the offense."
So, legally, a police officer only has the authority of a peace officer within the city where he is employed UNLESS given prior consent to act as a peace officer elsewhere. It is my understanding that almost all adjoining jurisdictions have given mutual consent. He also has the authority of a peace officer if there is danger, or if somebody is escaping (e.g., he has chased somebody into another jurisdiction).
However, a police officer in another jurisdiction still has the authority of a private citizen to make an arrest, which allows an arrest for any felony the citizen has probable cause to believe has been committed, and any misdemeanor committed in his presence.
Of course, on the Santa Monica Fwy you will be within the jurisdiction of all three agencies, so CHP, Sheriff, and LAPD officers all have the authority of peace officers without any need for consent or emergency. However, as a practical matter there is another limitation governing whether you will be pulled over for a traffic infraction (as opposed to a misdemeanor like DUI), which is that it is very doubtful that an officer will do so if he does not have a citation book with him.
Cited statute and
30+ years as a criminal defense attorney