There are various criminal charges for operating a motorized, electric, or otherwise-powered transportation device on public roadways or waterways while under the influence of or intoxicated by drugs or alcohol, as defined by state law. DUI, DWI, OUI, OWI, and BUI—driving under the influence, driving while intoxicated, operating under the influence, operating while intoxicated, and boating under the influence—are some of the common names for such impaired-driving or impaired-operating criminal offenses.

Laws regarding the definitions and names of such alcohol and drug-related driving offenses vary from state to state and are usually located in a state’s statutes—often in the penal code or criminal code.

In New Hampshire (NH), the relevant laws for operating a vehicle under the influence of drugs or alcohol are primarily found under RSA 265-A: Alcohol or Drug Impairment. The state uses the terms DWI (Driving While Intoxicated) and OUI (Operating Under the Influence) interchangeably to describe the offense of operating a motorized vehicle while impaired. New Hampshire law prohibits not only the operation of traditional motor vehicles while intoxicated but also extends to operating boats, OHRVs (Off-Highway Recreational Vehicles), and snowmobiles under the influence. The legal blood alcohol concentration (BAC) limit is 0.08% for drivers 21 years and older, 0.02% for drivers under 21, and 0.04% for commercial drivers. Penalties for DWI/OUI offenses can include fines, license suspension, installation of an ignition interlock device, and even imprisonment. Aggravated DWI, which involves higher BAC levels or other aggravating factors, carries more severe penalties. Additionally, NH has an implied consent law, meaning that drivers are deemed to have given consent to a chemical test (blood, breath, or urine) for the purpose of determining impairment. Refusal to submit to such a test can result in separate penalties.