The road between Middleton Cheney and Farthinghoe was closed for several hours and three people were taken to hospital following a car crash last weekend.
Just before 4.30pm on Sunday, October 14, fire fighters from Banbury and Brackley were called to the incident involving a blue Ford Mondeo and a white Citroen Berlingo on the A422.
Two people were trapped and the crews used hydraulic cutting gear to free both.
The 61-year-old man who was driving the Mondeo and his 58-year-old female passenger were both taken to Walsgrave Hospital in Coventry via air ambulance with serious injuries.
The 29-year-old woman who was driving the Berlingo was taken to John Radcliffe Hospital in Oxford by ambulance with minor injuries.
Northants police are asking to anyone saw the vehicles before the crash, or anyone who witnessed it, to call Drivewatch on 0800 174 615.