Sonoma County is a drinking destination. Roads swell with traffic on summer weekends when out-of-county visitors go tasting at more than 425 wineries and two dozen breweries that call the county home.
People line up for hours in downtown Santa Rosa every February to get their three 10-ounce glasses of Pliny the Younger triple IPA — a ration designed to prevent people from drinking too much of the high-octane 10.25 percent alcohol beer.
More than 7 million people come to Sonoma County annually, 4.6 million of whom cite beer and wine as their reason for visiting, according to the Sonoma County Economic Development Board.
While some locals blame beer-drinking and wine-tasting tourists for making Sonoma County roadways less safe, the fact is most drunken drivers in Sonoma County are residents whose last drink came at home, a bar or a restaurant.
A Press Democrat analysis of DUI arrest data from the California Highway Patrol Santa Rosa-area office shows people were five times more likely to be arrested on drunken-driving charges coming from a home than from a winery or brewery.
Every week, on average, more than 50 people are arrested on suspicion of driving under the influence of alcohol or drugs somewhere in Sonoma County, The Press Democrat found. The CHP, which makes nearly 40 percent of those arrests, collects data revealing where many were drinking before they got behind the wheel.
More than 35 percent told CHP officers they had been drinking at a bar or restaurant before they were pulled over, while more than 34 percent said they had been drinking at a home, The Press Democrat analysis found. Just under 7 percent told officers they were drinking at a winery or brewery.
The data come from CHP reports detailing where people say they had their last drink prior to a DUI arrest. While people aren't legally required to tell officers where they were drinking, they do more than half the time, and those are tabulated in so-called 'last drink reports.'
Of the 3,155 total DUI arrests made by the CHP in Sonoma County from 2015 to 2017, more than half — 1,672 — told officers where they had their last drink. Those arrests comprise more than one-fifth of the 8,074 total DUI arrests made by law enforcement agencies in Sonoma County over the three years.
The CHP data reveal some regional differences in DUI activity:
— Patrons leaving wineries and breweries account for a much higher proportion of DUI arrests in Healdsburg than other parts of Sonoma County. About 31 percent of respondents who were arrested coming from the Healdsburg area, or 39 people during the three-year period, said they had their last drink at a winery or brewery.
— The Graton Resort & Casino is named more frequently in CHP reports than any other single business in Sonoma County. About 38 percent of respondents arrested coming from Rohnert Park, or 72 people during the three-year period, said they had their last sip in the casino just outside the city's western edge.
— Visitors to state and regional parks account for a higher proportion of DUI arrests in west Sonoma County than other parts of the county. About 17 percent of respondents who were arrested while driving from west county, or 35 total, had their last drink at a state or regional park.
For decades, CHP officers have asked each person arrested in alcohol-related DUIs where they had their last drink. It helps the prosecution of DUI cases, said CHP spokesman Officer Jon Sloat. But it wasn't until 2015 that CHP-Santa Rosa started creating an annual 'Last Drink Analysis' to identify where suspected drunken drivers had been drinking.
'We were asking the questions, so we thought, 'Why not start putting it together in a report?' ' he said. 'But it's still pretty recent so it hasn't changed our policies or patrols.'
Responses found in the reports run the gamut — from parks, beaches and 'playing soccer' to supermarkets and 'dinner with Mom.' Around 4.5 percent of the people arrested on suspicion of DUI over the three-year period, a total of 30 people, told officers their last drink was at work.
The Sonoma County Department of Health Services has conducted its own 'place of last drink' survey for every city in Sonoma County since 2011. The survey is anonymous and is conducted through a county program that people convicted of driving under the influence must take to get their driver's licenses back.