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DUI Law

Driving under the influence of alcohol or other impairing drugs is a crime in all 50 states and the District of Columbia. Whether your state calls it "driving under the influence (DUI)," "driving while intoxicated (DWI)," or some other name, it is a charge that is taken very seriously and punished accordingly. The National Highway Traffic Safety Administration (NHTSA) estimates that roughly 40 percent of all U.S. traffic deaths are alcohol-related to some degree.

FindLaw's DUI Law section covers a wide spectrum of issues pertaining to impaired driving, including court procedures, different types of charges, how to defend against a DUI charge, common penalties, state law summaries, and more.

What Does it Mean to be Impaired?

For the purposes of DUI law, generally you are "impaired" if your ability to safely operate a motor vehicle is appreciably affected by having consumed alcohol, illicit drugs, or prescription medications. Since everyone is affected differently by different substances, "per se" laws set measurable limits. For instance, motorists who are shown to have a blood-alcohol concentration (BAC) of at least 0.08 percent are assumed to be impaired. Similarly, some states assume that any amount of certain drugs in the bloodstream constitutes impairment.

How Did DUI Laws First Come Into Existence?

New York became the first state to enact drunk driving laws in 1910. California and a handful of other states followed one year later, but none of these statutes offered a specific definition of what it meant to be drunk or impaired. Instead, proof of intoxication was left to the arresting officer's observations. Therefore, these early laws were not very enforceable.

States realized they needed an objective way to measure a driver's impairment, which led to the invention and enthusiastic adoption of the "Drunk-o-meter" in 1938. The following year, Indiana became the first state to establish a BAC limit (at .15 percent, which is nearly twice the current limit). As BAC-monitoring technology steadily improved, other states began setting their own BAC limits to enforce drunk driving laws.

When Did State DUI Laws Become Uniform?

States with impaired driving laws were strongly encouraged by the American Medical Association and federal agencies to set BAC levels at 0.15 percent or lower, but they were free to establish their own guidelines. States also had different drinking ages, ranging from 18 to 21, but research showed that higher drinking ages correlated with lower drunk driving rates.

This changed in 2000, when Congress passed a law requiring each state to set its BAC limit at 0.08 percent and establish the drinking age at 21. Since the penalty for noncompliance was the loss of millions of dollars in federal highway funds, all states eventually fell in line. In 2013, the National Transportation Safety Board suggested lowering BAC limits to 0.05 percent.

How Can a DUI Lawyer Help Me?

A drunk driving conviction can lead to steep fines, loss of driving privileges, and even jail time. Additionally, it could affect your job security and significantly raise your insurance rates. Since the stakes are typically fairly high, it usually pays to have a DUI attorney handle your case. Your attorney will be skilled at scrutinizing the evidence against you, ensuring that your rights are protected, and securing the best possible outcome.

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