Footage of the incident shows the bird on the A170 near Helmsley in the early hours of 30 November.
The officer can be seen approaching the owl and gently coaxing it into eventually flying away.
The video has prompted speculation from ornithologists as to the animal's unusual behaviour.
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Dr Tim Mellings, from the RSPB, said: "My first impression is that this is not normal behaviour.
"Any bird which sits in the middle of the road like that and allows somebody to walk right up to it is not behaving normally and is unlikely to live long as it's a target for predators.
"The most likely explanation is that a previous car has clipped the bird and left it stunned.
"If it was a perfectly healthy owl it would not have been sitting in the middle of the road; owls come down to the ground to catch prey and the rest of the time they are off the ground where they are safe."
Laurence Whitaker, of the BBC's Winterwatch, said the bird could have been startled by the vehicle's headlights.
"A lot of barn owls will use these roads to hunt and sadly a lot of them do get run over," he said.
"I think the one in the was probably startled by the headlights, sort of like a rabbit in the headlights, and didn't want to move anywhere."
A "stunned" barn owl was spotted sitting motionless for up to a minute in the middle of a country road before being rescued by a police officer.