The A14 is closed will remain closed for much of the day following after a serious crash earlier today (Wednesday).
The road is currently closed eastbound between the M1/M6 junction at the Catthorpe Interchange and junction one near Welford following a serious collision involving a van and a lorry at 5.30am.
It is expected to remain closed until late afternoon, early evening while investigations continue.
HGVs held within the closure are now proceeding ahead past the crash scene in the outside lane after clearance was given by police.
The westbound side was also closed for several hours following the crash but reopened at around 8.15am.
A spokesman for Northamptonshire Police said: "Motorists are being advised to avoid parts of the A14 following a serious road traffic collision between the M1 and Junction 1 of the A14.
"This section of the eastbound carriageway has been closed after a van was in collision with a lorry shortly before 5.30am this morning.
"Eastbound is expected to remain closed for the morning to allow emergency services to deal with the collisions."
Highways staff have been trying to turn traffic around at the back of the queue for several hours.
Highways England tweeted: "If you are caught within the closure on the #A14 E/B btwn #Catthorpe #M6 #M1 and J1 we are working to get you moving ASAP.
"If you have any welfare issues/ need medical assistance, please call the emergency services. For any further updates, please keep monitoring @HighwaysEMIDS"
A later tweet added: "Police investigations are on going and the road is expected to remain closed until late afternoon, early evening."