There are severe delays of at least 30 minutes on the A14 after a lorry fire.
Highways England said: "The A14 is currently closed from J21 (Brampton) to J16 with delays of at least 30 minutes covering several miles of the westbound carriageway. This closure is due to a vehicle fire and Highways England has resources deployed working hard to restore normal conditions as soon as possible.
"For traffic approaching the closure locally, you are advised to expect disruption with extra journey time and may potentially have to re-route your journey.
"If travelling towards this area from much farther afield, you may wish to change your strategic route, allow extra travel time and follow guidance from our on-road variable message signs and media.
"Please note, the diversion route (if followed) below brings traffic back on at J13 (Thrapston):
"Road users are advised to follow the "Hollow Yellow Circle" diversion symbol and exit the A14 westbound, turn right (4th exit) at the Brampton Hut Interchange Roundabout and take the exit slip road for the A1(M) north.
"Continue on the A1(M) north, past Alconbury, Sawtry and Stilton towards Peterborough. At the A1(M) J17 interchange, take the northbound off slip road and the first exit at the roundabout on to the A605 west. Continue on the A605 past Elton, Warmington, Oundle and Thorpe Waterville to re-join the A14, J13 Thrapston.
"Further incident information is available from Highways England by visiting our www.trafficengland.com website and travel apps, or via our @HighwaysEAST regional twitter feed. For urgent real time assistance, our 24/7 contact centre team is able to provide up to the minute information on 0300 123 5000.
"Highways England has been working closely with our emergency services colleagues Cambridgeshire police, who led the response to this incident."