Hampshire Police are appealing for witnesses after a collision on the northbound A331 at Farnborough Gate.
The collision between an HGV and a BMW took place at around 6.45pm on Saturday 22 July.
The male driver and female passenger of the car sustained serious injuries.
The driver of the HGV has been arrested in connection with the incident and remains in custody.
The northbound carriageway of the A331 was closed for several hours.