If you visit an Emeryville bar or restaurant over the holidays, don't be surprised if you see an officer asking for volunteers to take a breathalyzer test.
They aren't makings arrests, just trying to educate patrons on the effects of alcohol and whether they think they are safe to drive.
Volunteers will be asked if they can guess their blood-alcohol content during the "Know Your Limit" outreach effort.
The legal limit is .08 percent, which amounts to two drinks consumed by a 120-pound woman within an hour or four drinks by a 180-pound man, authorities said.
"The goal is to help people understand the effects of alcohol, so they can make smart decisions about how they get home after a night of drinking," Emeryville police said in a news release.
Those participating will be asked how many drinks they had and if they think they are safe to drive. After the test, officers will talk to them about the impacts of alcohol on driving and the consequences of a DUI arrest.
Height, weight, food intake, drugs and medication -- along with how much alcohol is consumed over a time period -- are all factors that affect blood-alcohol content.
One drink is based on 1.5 ounces of liquor (40 percent alcohol), 12 ounces of beer (4.5 percent alcohol) or a 5-ounce. glass of wine (12 percent alcohol). In addition, the body lowers the BAC level at a rate of .015 percent every hour, police said.
The average cost of a DUI arrest is about $13,500, which includes vehicle impound fees, fines, attorney fees, auto insurance hikes and other penalties, according to police.
Those who plan to go out drinking should to designate a sober driver, police said.