Hamilton police made 538 impaired-driving arrests in 2012, up five from 2011.
"That's a 15-year high," Catherine Martin, a spokesperson for Hamilton Police Services, told CBC Hamilton on Thursday.
She said 166 of those arrests stemmed from the force's Operation Lookout campaign, which implores citizens to call police if they suspect they've spotted an impaired person operating a vehicle.
"What we've been encouraging people to do is to call 911 because we consider that a crime in progress."
Hamilton police stopped a total of 228,315 drivers as part of the force's RIDE programs — "the most ever" — Martin added.
In contrast, they checked about 170,000 vehicles in 2011.
"It speaks the value of policing," Martin said. "It's about the investment in policing and the results that can happen."
Martin said on Thursday she didn't have precise figures on how many drunk-driving arrests police made during the holiday season, but the numbers would be available in the coming days.
'There's a lot of work that'll still have to be done'
The Ontario Provincial Police charged 693 people across the province with impaired driving during its holiday season RIDE campaign, which ran from Nov. 24 until Jan. 2.
That tally represents an eight-year high, according to the OPP.
"We had hoped to see these numbers decrease significantly during this year's campaign," OPP Commissioner Chris Lewis said in a statement.
"It is disappointing that we still have Ontario drivers who feel entitled to place other road users at risk of losing their lives."
In 2012, the OPP laid around 8,000 impaired-driving charges, said Dave Woodford of the Highway Safety Division. Last year's total was roughly equal to that of 2011.
However, the service saw an uptick in the amount of fatal accidents that involved alcohol.
"We had 72 fatalities that were alcohol-related," he said. "That's up from 60 the year before."
"So there's a lot of work that'll still have to be done. "