When a peace officer stops a suspect after witnessing a drunk driving offence, what is the procedure for placing the suspect under arrest?

When a peace officer stops a suspect after witnessing a drunk driving offense, he may summon a highway patrol officer and the latter may administer the sobriety test, place the suspect under arrest, and request him to submit to a chemical test. (Freeman v. Department of Motor Vehicles (1969)70 Cal.2d 235, 74 Cal.Rptr. 259, 449 P.2d 195.)

3. A peace officer may, without a warrant, arrest a person involved in a traffic accident when the officer has reasonable cause to believe that such person had been driving while under the influence of intoxicating liquor or under the combined influence of intoxicating liquor and any drug. (Veh.Code, 40300.5.) The term "traffic accident" means an accident involving at least one vehicle, which occurs either on a public street or elsewhere. (People v. Ashley (1971) 17 Cal.App.3d 1122, 1126-1127, 95 Cal.Rptr. 509.)