The decision is one of weighing the likelihood of a high blood-alcohol reading against the consequences for refusing. If you refuse, your license will be automatically suspended for a period of time. The length of suspension depends on whether it is your first or subsequent refusal to submit to a chemical test. For example, a first refusal results in a 12 month suspension. If you take a chemical test and your blood alcohol level is over .08, this is evidence that will be used against you to prove you were driving under the influence.