A Washington State DUI is not committed by simply driving a car on a public highway after having consumed alcohol. Thousands of Washington citizens drive their cars after having had something to drink at a social function or gathering, including the holidays. They do so safely if they did not drink enough to become impaired. Unimpaired driving, even after consuming alcohol, is not a DUI under Washington State law. Citizens drive legally if in addition to lack of impairment, they did not drink enough to exceed Washington State's DUI legal limit of .08. It is a fact of life today, however, that drinking any alcohol before driving places the driver in the sights of DUI law enforcement efforts and can result in the driver's arrest.

The crime of DUI occurs in Seattle or elsewhere in Washington state when one drives an automobile on the public highways of the state with an alcohol concentration at or above the legal limit. The DUI legal limit in Washington State is "0.08." This is a very low standard, considering that the average person can reach the legal limit with only a couple of drinks. For example, two (2) pints of beer at the local pub within one hour might be enough to get a 200–pound male to reach the legal limit. Similarly, two (2) glasses of wine within one hour might be enough to get a 120–pound woman to reach the legal limit. There are a number of variables, however, so two individuals who weigh the same and who drink the same amount might feel different levels of impairment and might also have different blood alcohol levels. It is very difficult, perhaps impossible, for an individual who has been drinking to predict his or her blood alcohol level and thus, many drivers who thought they were below the "legal limit" are surprised to find that their breath tests result exceeded the .08 limit.

Moreover, according to many forensic scientists, a person may feel the effects of alcohol, such that his or her ability to drive safely may be impaired, at levels below the legal limit, such as "0.05" or "0.06." You must keep in mind that you can be arrested for and convicted of a Washington State DUI at an alcohol concentration below the legal limit, as long as the prosecution can prove beyond a reasonable doubt that your ability to drive was affected to any appreciable degree. In this regard the ".08 DUI Limit" road signs that we see only tell half of the story. The other half of the story is that a DUI conviction can occur even if the reading is under .08. This of every DUI charge in Washington State.

You should also keep in mind that many individuals may not appear to be affected by alcohol at the legal limit. A driver may be functioning perfectly well, although under Washington law he or she is legally drunk. Washington State's DUI law is actually a two-pronged prosecution presenting the questions (1) was the driver over .08 and (2) was the driver's ability to drive appreciably impaired by alcohol. These apparently simple questions are factually complex to answer, but it is the prosecution's burden to prove these propositions beyond a reasonable doubt in a Washington State DUI prosecution.

In past years some municipalities had different "per se" limits. Thus, a Seattle DUI charge could have a different proof level than a Bellevue DUI charge or a Kirkland DUI charge. However, now the law is uniform: Anywhere in Washington state a DUI is committed by either being impaired or being at or over the .08 DUI legal limit.