Officers shut down the major road after drivers saw the body part in the central reservation - but it turned out to be a fake.
The road, which connects Doncaster to the north east, was closed by the Cleveland and Durham Roads Policing Unit near Middlesbrough yesterday to investigate.
But they later revealed the grisly discovery was actually a realistic-looking prop.
Afterwards the unit went on Facebook to explain the closure.
It said: "In a nutshell, an eagle eyed diligent member of the motoring public spotted a suspicious looking item in the central reservation.
"Officers have attended and it has been found to be a realistic looking 'severed hand'.