The officers looked for signs of alcohol or drug impairment on the eve of the holiday.
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Police will continue to conduct similar operations across the country this weekend as thousands enjoy the celebrations at bars and parties.
Authorities will be on the lookout for drunk drivers, but now that recreational marijuana is legal in California, they are also warning drivers that a DUI doesn't mean just booze.
"We can still see the symptoms there based on objective symptoms that someone displays. What we do is we do a field sobriety test after that. Then we have drug recognition experts that will take another look at that individual," Lt. Manuel Romeral said.
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Drivers under the influence will be arrested at the checkpoints, but authorities said one of their main goals is to educate drivers and prevent them from hurting themselves or anyone else.
"We're hoping that as other motorists drive by and they'll see and think twice about having that drink or smoking and driving a vehicle," Romeral said.
Authorities encourage people who go out to celebrate to use a rideshare service, a taxi, or a sober friend.