To add to Codee's post


■ California Penal Code (CPC) 1463 states:
The following definitions shall apply to terms used in this chapter:
(a) "Arrest" means any law enforcement action, including issuance of a notice to appear or notice of violation, which results in a criminal charge....



■ California Vehicle Code (CVC) 40600.
(a) Notwithstanding any other provision of law, a peace officer who has successfully completed a course or courses of instruction, approved by the Commission on Peace Officer Standards and Training, in the investigation of traffic accidents may prepare, in triplicate, on a form approved by the Judicial Council, a written notice to appear when the peace officer has reasonable cause to believe that any person involved in a traffic accident has violated a provision of this code not declared to be a felony or a local ordinance and the violation was a factor in the occurrence of the traffic accident. ...

■ California Vehicle Code (CVC) 40300.5
In addition to the authority to make an arrest without a warrant pursuant to paragraph (1) of subdivision (a) of Section 836 of the Penal Code, a peace officer may, without a warrant, arrest a person when the officer has reasonable cause to believe that the person had been driving while under the influence of an alcoholic beverage or any drug, or under the combined influence of an alcoholic beverage and any drug when any of the following exists:
(a) The person is involved in a traffic accident.
(b) The person is observed in or about a vehicle that is obstructing a roadway.
(c) The person will not be apprehended unless immediately arrested.
(d) The person may cause injury to himself or herself or damage property unless immediately
arrested.
(e) The person may destroy or conceal evidence of the crime unless immediately arrested.



Obviously, the presence of drugs is essential too!