.08 BAC Legal Limit
Today, the United States has a national blood alcohol concentration (BAC) standard of .08 that is based on more than 30 years of scientific evidence. The nation has come a long way since the first commonly-used legal limit for BAC, .15, was adopted in 1938.
The science on how alcohol affects a person’s driving skills has evolved over the years. According to the National Highway Traffic Safety Administration (NHTSA), although outward appearances may vary, virtually all drivers are impaired at .08 BAC. Laboratory and on-road research shows that the vast majority of drivers, even experienced drivers, are impaired at .08 BAC in critical driving tasks such as braking, steering, lane changing, judgment, and divided attention.
Responsibility.org led the distilled spirits industry in supporting the passage of .08 BAC laws as part of a comprehensive solution that included BAC education and public awareness of the law. We worked with Mothers Against Drunk Driving (MADD) to assist states in advocating for the passage of .08 BAC per se laws. By 2004, every state had passed a .08 BAC per se law. Delaware was the final state to enact the law.
You can learn about how alcohol affects BAC levels at our Virtual Bar. Here’s one example: A 170-pound man can consume approximately four drinks in an hour on an empty stomach before reaching a .08 BAC. A 137-pound woman could drink three drinks in one hour on an empty stomach before reaching a .08 level. Studies show that the fatal crash risk at .08 BAC is at least 11 times that of a sober driver.