I had this issue again, yesterday, in a Boise DUI (driving under influence) case before an Ada County Magistrate Judge.  The answer may not be as simple as the City of Boise would argue.  They contend that an arrest does not occur until the handcuffs are on the defendant – and that usually does not occur until after the field sobriety tests.  Accordingly, the defendant is not in "custody" and there is no obligation to provide Miranda warnings.  My case involved a defendant who had been arrested going the wrong way down a one way street in Boise, after 2:00 a.m.  With the bars closing and his driving pattern, the officer made a stop with his lights flashing and approached the car.  He testified that he smelled the odor of alcohol, and that he observed the bloodshot and glassy eyes of my client.  His next question:  Have you been drinking tonight?  Was there a duty to advise the defendant of his right to remain silent?  Answer:  not yet.  The judge ruled that there was no arrest for Miranda purposes until further investigation had occurred.  That "investigation" was the officer administered field sobriety tests.  Statements made by my client during those tests are admissible, as is the breathalizer result.  The message here – you are not going to hear the officer tell you that you may remain silent until after you have taken the field sobriety tests.  Of course the case has not been tried yet, and the breathalizer results are not 100% accurate.  Still at issue – whether the state must provide the source code for the Intoxalizer 5000, and whether the defendant’s BAC is admissable and enough to prove that he was operating the car while intoxicated.  Don’t drink and drive.  The cost is simply too high.  Have a question about drinking and driving in Boise Idaho?  Comment or send me an email.