The A27 near Lewes was closed or partially closed for about three hours yesterday (Monday 13 January) after a lorry and car crashed.
Traffic was reported to be much heavier than usual during the afternoon rush hour, with long queues and many forced to find alternative routes.
A light-coloured Seat was written off in the crash although the driver escaped with only minor injuries.
Although an air ambulance was dispatched to the scene, the injured driver was taken to hospital by road by the South East Coast Ambulance Service.
The trunk road was closed to eastbound traffic at the Southerham roundabout from about 3.30pm to about 6.30pm.
Sussex Police said: “Police are investigating a two-vehicle collision in Lewes on Monday afternoon (13 January).
“Emergency services were called to the A27 eastbound towards the Beddingham roundabout, just before 3.30pm, to reports of a collision between a Seat and a DAF Truck.
“The driver of the Seat suffered minor injuries.
“The road was closed while services worked at the scene and the vehicles were recovered.
“Anyone who witnessed the incident or has any relevant dashcam footage is asked to contact police online or via 101, quoting serial 683 of 13/01.”