Three nursing students who made a 130-mile (209km) round trip to buy fish and chips have been fined for breaching lockdown.
The trio had travelled from Leeds to Filey on Saturday with three other students, North Yorkshire Police said.
Officers also issued more than £16,000 in fines after finding 21 people at a 40th birthday party in Scarborough.
It said there had been a "marked change" in behaviour since plans to ease England's lockdown were revealed.
Supt Mike Walker said officers had issued 255 fixed penalty notices since Boris Johnson announced the proposed roadmap out of Covid-19 restrictions, a 33% increase on the previous week.
He said people were "starting to relax their approach to the national lockdown" and warned that failure to stick to the rules could see government plans delayed.
"We are not home and dry yet," he said.
"Yes, we know the vaccination programme offers great hope, but we are not at the point where we can abandon social distancing and all other precautions and just throw caution to the wind.
"The prime minister said very clearly that the roadmap will be led by data not dates, so let's not jeopardise that now."
North Yorkshire's Local Resilience Forum heard, of the 255 fines issued, 119 were given to people from the county and 136 were given to visitors.
Among those fined were nine people from Hull who drove to Filey for a barbecue and a man, from Harrogate, who was stopped while driving at 126mph (203 km/h) having been to York to collect a female passenger for a drive to Scarborough.
Sgt Dan Thompson, based in Eastfield in Scarborough, added: "People are really just letting slip."
On the case of the six students from Leeds, he said: "We've found that most of the breaches of late are from people that we would not ordinarily expect to encounter."
Since the start of the third lockdown in January the force has issued 1,272 fines.