Miranda warnings don't apply at the side of the road. The police do NOT have to read you the Miranda warning until you are in custody. When the police are talking to you at a traffic stop, they are gathering the evidence they need to determine if you can be arrested for DUI. They can, and will, ask you all kinds of questions during this process. Since you are not "in custody," they do not read the Miranda warning to you before they start asking you questions.
Officer Friendly knows how to make general statements designed to have you offer evidence in the spirit of cooperation. Thus you are not being questioned when Officer Friendly says "I'd like you to do these field sobriety tests to see if you're safe to drive." What he means is:
"I smell alcohol, but before I arrest you for DUI, I need more evidence.Will you admit that you've been drinking?Will you try these tests that have no correlation to driving that are designed for failure so I can capture you looking ridiculous on a camera that may or may not be working? Then, I'll have enough evidence to convict you of DUI."Don't play along. Don't talk to Officer Friendly. Unless you really want to incriminate yourself.
What will the officer do when you refuse? He has a few choices.