A white Kia was caught on dashcam driving the wrong way down the A14 westbound carriageaway at Levington
The footage, captured by Robert Coppin on Saturday, saw the driver on the outside lane heading towards oncoming traffic.
Stunned witnesses say the white vehicle was heading eastbound towards Felixstowe, on the westbound carriageway
The vehicle is understood to have joined the A14 at either Levington or the Seven Hills roundabout.
A spokesman for Suffolk police confirmed the incident was being investigated and witness statements are being sought.
He said: “The driver was going eastbound down the westbound carriageway and we received a number of reports yesterday.
“The incident is under investigation by our roads and armed policing team.”