Roadside Sobriety Evaluations are NOT scientific tests. In fact, these exercises are 100% optional in EVERY state. The original research done in the 1970s by Burns, Moscowitz and others only showed that a percentage of drivers who failed would have an alcohol level of 0.10 grams percent, but not anything close to 100%. Roadside conditions, slope, grade as well as the person's physical agility and inherent ability to balance play a huge role in these evaluations. Because these tests are optional, and carry no penalty for declining to attempt them, the best advice is to politely say "NO". If you don't heed this advice, you will find that these evaluations will be the #1 item of evidence introduced against you at trial.