A 52-year-old woman was seriously injured after her Land Rover Defender crashed with a blue Mitsubishi Fuso truck.
She was driving along the B4525, Welsh Lane, near Helmdon just before 9am when her car was in collision with the truck.
East Midlands Ambulance service arrived at the scene shortly afterwards.
Witnesses are asked to call the Northants Police Drivewatch hotline on 0800 174615.
More on this when we get it.