Drivers accustomed to traveling slightly over posted speeds might be in for a different kind of Christmas surprise this weekend as CHP officers will be ramping up speed limit enforcement.

In addition to the CHP’s efforts, law enforcement agencies throughout the county are increasing the number of police on roadways to spot drunken and drugged drivers through the New Year’s.

Petaluma and Santa Rosa police officers have worked overtime, funded by grants from the California Office of Traffic Safety, for additional DUI patrols since Dec. 15. Their state-funded efforts will continue until Jan. 1.

Santa Rosa police will also conduct a DUI checkpoint at a yet-to-be disclosed location between Christmas and New Year’s Day, said Sgt. Michael Chad Heiser. The date and time of the operation will be announced beforehand. The Sonoma County Sheriff’s Office is not increasing staffing levels for the holidays but patrol deputies will be “extra vigilant” for signs of impaired driving, said sheriff’s spokesman Sgt. Spencer Crum.

On highways throughout Sonoma County, CHP has dubbed Christmas weekend, Dec. 22-25, and New Year’s weekend, Dec. 30-Jan. 1, a “maximum enforcement period.” The focus will be on speed limit enforcement, which often leads to more DUI arrests, said CHP Officer Jon Sloat.

“Officers won’t give drivers leeway for going 5 or 10 mph over the speed limit they might normally,” Sloat said. “And every traffic stop is a DUI investigation.”

CHP recorded 19 DUI arrests, 44 traffic accidents and one fatality during the period of ramped- up holiday enforcement in 2016, Sloat said.

A deadly November in Sonoma County with at least five people dying in DUI-related accidents sparked concern among law enforcement that driving under the influence might be on the rise.

But total DUI arrests and accidents have stabilized on county highways, Sloat said. “Our numbers aren’t any higher, we just had a cluster” of fatalities last month, he said.

Law enforcement’s annual increase of well-publicized DUI patrols is also an effort to reduce drunken driving as much as a response to a time of year where people often overindulge, officials said.

“This a public awareness campaign about the dangers of DUIs,” said Petaluma Police Lt. Tim Lyons. “Hopefully, that’s finally kicking in.”

Holiday DUI numbers differed between Petaluma and Santa Rosa in 2016. Last December there were 39 DUI arrests in Petaluma, well above the monthly average of 26.5 for the year, Lyons said.

Santa Rosa, on the other hand, saw a sharp decrease in December 2016 DUI totals. Santa Rosa police made a total of 30 DUI arrests last December, down from a monthly average of 41.8 DUI arrests, according to publicly available data.

Heiser hopes police departments’ concerted public awareness effort makes people think twice about drinking and driving. “That could be an explanation for the drop in number over the holidays,” he said.

You can reach Staff Writer Nick Rahaim at nick.rahaim@pressdemocrat.com.