Motorist John Turner, who lives near Wymondham, saw the van moving slowly with its hazard lights flashing in London Road in the south Norfolk town last Wednesday.
Mr Turner posted footage from his dashcam of the van onto a community Facebook page called Wymondham Ways, and it was then brought to the attention of Royal Mail.
The organisation has suspended the driver while the incident, which happened on June 8 at 9.11am, is investigated.
Royal Mail spokeswoman, Morag Turnbull, said they were taking the footage seriously.
“Royal Mail can confirm that a postman from Wymondham has been precautionary suspended whilst an internal investigation takes place into this matter,” she said.
“Royal Mail takes any incident of illegal or dangerous driving seriously and anyone caught doing so will face serious disciplinary measures.”
Mr Turner said he was taken aback when he saw the delivery van driving on a part of the road usually reserved for pedestrians and cyclists, which was otherwise empty at the time.
He said: “It’s quite clear that part of the road is not meant for motor vehicles.
“I don’t want to get anyone into trouble, but on the other hand if that were to become standard practice, before you know it you are not going to have a safe place for cyclists and pedestrians.
“There is sometimes an attitude that if people switch their hazard lights on then they can do whatever they want.”
Mr Turner said it was the most remarkable thing he had seen since having a dashcam installed a couple of months ago.
He said: “Occasionally it catches boy racers whizzing past. But when I saw that with the orange flashing lights I was quite startled.”
Reaction to Mr Turner’s Facebook post with the video has been mixed, with some people seeing no harm in the driver’s actions.
Matthew Smith posted: “Don’t see anything too wrong with it! I’ve seen postmen doing this on this road for years now.”
Heidi Standley posted “I’m probably going against the majority here, but he/she is putting nobody in danger, I see no issue. I’m sure if there were pedestrians they would wait for them to pass.”
But Andrina Carvell pointed out: “It’s a path not a road.”
