Double yellow lines have been painted in an alleyway that is too narrow to drive down.
Lines have been painted on both sides of the passageway, off Newhall Street in Swindon, leaving a gap of just 13in (33cm).
Nathalie Fisher, a local resident, said it was a "bit of a mystery" as "you couldn't even fit a motorbike down it."
Swindon Borough Council said the authority will be "taking it up" with their contractors.
'Forgot car size'
Ms Fisher, who lives on Newhall Street, said it had been "good that the council came around to clean all of the back alleyways up".
She added: "But to find out the only reason was to double yellow everything they could physically see was a bit of a mystery."
The council said local residents had asked the authority to "deal with illegal parking in alleyways".
A spokesman said: "It seems that our contractors forgot just how big cars actually are when they painted this one.
"We will be taking it up with them."