NOVATO, Calif. (KTVU) - St. Patrick's Day falls on a Saturday this year, adding to the party potential, and the DUI risk.
Bay Area law enforcement was already out with saturation patrols Friday night, and two cities held DUI checkpoints: Redwood City and Novato.
"A perfect night would be nobody under the influence, nobody gets hurt, and we all go home safe tonight," said Sgt. Nick Frey, who administers Novato's checkpoints, funded by federal grant.
The screening started at sunset on busy Novato Boulevard."I think it's a little early for people to be drinking, what is it 7 o'clock?," said one driver.
But drunken driving isn't confined to the wee hours, especially the night before St. Patty's, which has long had a reputation as a drinking holiday.
Drivers passing through are asked to show their driver's license, and asked if they've had anything to drink.
They drive away with a flyer about DUI, and perhaps a heightened awareness of the dangers.
"There is devastation caused by those who just don't take the simple steps," said Novato Police Lt. Mike Howard.
At Novato P.D.'s last checkpoint, during the holidays, a man drove through so drunk he didn't see the lights, cones, and officers, who had to jump out of the way.
"If they can't see a checkpoint, I'm concerned about what they're not seeing just driving down the road," said Howard.
Across town, at Moylan's Brewery and Restaurant, staff readied for a busy weekend.
"I'll be behind the bar tomorrow night when the bagpipes arrive," said Eileen Moylan, part of the family that has run the brewpub since 1995.
The beer is ready to flow, and hundreds of pounds of corned beef are ready to boil, but Moylan says it's important that the party stay in check.
"You can't over-serve, it's illegal to over-serve somebody so all of our bartenders are trained very well.
"Moyland says even in a busy environment, they stay aware of customers who might over-indulge.
"We ask if they have a ride home, are they driving? We get them rides, and we've driven people home," said Moylan, "because everybody's got to be responsible."
She likes to keep the focus on what it really means to be Irish.
"You never go hungry in an Irish home, and you'll always be welcome in an Irish home."
Unfortunately, St. Patrick's day is statistically, a dangerous time to be on the roads.
"What people say is, I'm okay to drive, or I felt I was ok to drive," said Lt. Howard, "but it seems the point you start contemplating whether or not you're okay to drive, you're past that point," added Sgt. Frey. "There are so many opportunities out there to get Lyft or Uber, rideshare, or just don't do it at all. We don't want people getting hurt."
By 11 pm, close to 1,800 vehicles had passed through the checkpoint, thirty pulled out of line for screening, and three drivers field tested for DUI.
But because deterrence is the goal, a checkpoint's success is measured more by how few people are impaired, not how many.