Criminal law — Driving under influence — Evidence — Statements of defendant — Accident report privilege — Defendant’s statements during crash investigation are not protected by accident report privilege where defendant did not report accident and fled scene — Pre-Miranda statements made during roadside criminal investigation are admissible where casual conversation during which statements were made did not constitute custodial interrogation, statements were spontaneously made, and defendant was not subject to formal arrest when statements were made — Post-Miranda statements are admissible where statements were made knowingly, intelligently, freely, and voluntarily after waiving Miranda rights