Ever imagine yourself having to perform a field sobriety test after being pulled over? Imagine you have had one beer, truly one beer and the officer says to you, "I smell alcohol, you've admitted to drinking a beer and you have bloodshot eyes. Would you like to perform some field sobriety tests?" Okay, you really have two choices here, (1) try and pass these feats of balance and concentration or (2) get arrested (they will arrest you if you refuse, guaranteed!) Not to worry though, as I have recently posted the "refusal" to participate in these tests cannot be used against you to show a "consciousness of guilt."
Notice how I used quotations around the word refusal in that last paragraph. That's because those tests are voluntary, yes you are under no legal obligation to perform them, no matter how the officer phrases it, don't do them. Anyway, the officer will undoubtedly testify that you "REFUSED!!!!" the voluntary tests, in an obvious attempt to imply you were uncooperative when in reality all you really did was exercise your right to not participate in evidence gathering, much as you would not participate in questioning at a police station without the presence of an attorney. I like to point out to juries all the time, how can someone refuse something that is essentially free. For example, if my friend offers me a piece of candy and I say no, did I REFUSE or did I simply decline their offer. If I had a free choice to make and didn't want to eat it because I'm allergic, I'm on a diet, etc. all I really did is politely say no. But in the DUI context the government and officers (trooper, sheriff's deputies, etc.) will imply that you somehow did not want to willingly participate is these "simple" little tests. Ha, these tests are hard. Just check out the two videos as reference (obviously they are exaggerations but you get the point). Field Tests are Hard! Field Test Passed but still arrested because he was drunk!
Bottom line is, if you have had anything to drink, politely say to the officer, "I'm not intoxicated and know I would pass your tests, but I have been advised not to take them." Especially don't take them if there is no video present. Nevertheless, I advise against them altogether.