Police are stopping drivers from crossing Yorkshire boundaries which are controlled by different lockdown rules.
Officers turned vehicles around as they attempted to leave the Tier 3 lockdown in East Yorkshire into the Tier 2 region of North Yorkshire.
To stop the spread of coronavirus, on-the-spot checks are being carried out by officers according to North Yorkshire Police.
The force have confirmed drivers travelling from Tier 3 into Tier 2 areas could face "enforcement action" for non-essential journeys.
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Residents in Tier 3 areas like East Yorkshire are warned by officers to stay away unless they need to travel into a Tier 2 area for work or education.
Superintendent Mike Walker, of North Yorkshire Police, said: "I realise there may be some confusion over what is deemed necessary in these circumstances, so I’d like to be clear here: it is neither necessary or acceptable to leave a Tier 3 area and enter a lower tier area for a day trip or to visit a pub or restaurant for a meal.
"Please also be reminded that your tier restrictions travel with you and police can take enforcement action against you, if you should breach those restrictions."
Police will be out patrolling and will be guarding the border areas.
Safety camera fleets, which are equipped with ANPR, will also be touring various routes into the region.
People are urged to not try to "side-step" restrictions in order to reduce the risk of Covid-19 transmission to residents.
“Those living in Tier 3 areas are advised not to travel out of the area unless it is necessary, such as for work or education," said Supt Walker.
“To those living in Tier 3 areas, please do not try to side-step the tighter restrictions in your area by visiting neighbouring Tier 2 areas for a day or night out. If you do, you may inadvertently bring the virus in with you and increase the chance of transmission to local residents.
“North Yorkshire is well-known for its hospitality and warmth, but right now we have to ask visitors to stay in their own tier area for the health and safety of our most vulnerable residents.
"If you have a visit planned, please reschedule to a time where we are able to give you a proper welcome to our beautiful county.”