Impaired driving refers to being in control of a motorized vehicle (including motorcycles, passengers cars, boats, and off-road vehicles) while under the influence of alcohol or other drugs. Symptoms of impairment include reduced ability to react and make decisions; reduced ability to control the vehicle; and increased reaction times. With respect to alcohol, drivers may feel the impaired effects of drinking before they reach the federal blood alcohol concentration (BAC) of 0.08%. Crash risk increases dramatically when drivers are impaired.