Originally Posted by Kerlenbach

You are not required in Florida to take a roadside sobriety test, either when driving or biking. For a driver, the officer can require you to take a breath test only after you have been arrested. To make a lawful arrest for DUI, the officer must have probable cause to believe you are driving while impaired. To determine if you are impaired, the officer gives you the roadside sobriety tests. If you refuse to take the test, the officer must use other evidence to determine whether you are impaired, like a driving pattern, speech, and your other actions. Once the officer makes an arrest, you have to take the breath test or risk losing your license. If you're tired, not feeling well, or, for that matter, drunk, there's not much sense in doing the roadsides. Just politely say, "thank you, but no." One does have the right not to provide evidence against oneself. Only after you are legally arrested do you have to take a breath test.
If you are concerned about these things, talk to a lawyer who defends DUIs, or one who prosecutes them. Don't rely on a book, a police officer (especially the one who is threatening you if you don't cooperate), or, worst of all, your pal who's had a few DUIs.