The one vehicle collision happened at around 8:10pm on Saturday on the southbound carriageway at junction 1A and involved a red BMW 3 series. A 29-year-old man suffered serious injuries and was taken to Edinburgh Royal Infirmary for treatment. Sergeant Scott Sneddon said: “Our investigations into the collision are ongoing and we are reviewing CCTV as well as speaking to a number of witnesses. We would urge anyone who hasn’t spoken to us but saw the vehicle prior to the collision, or the incident itself to come forward.”