The man, from Doncaster, was arrested and questioned after the lorry he was driving collided with a black Vauxhall Zafira on the eastbound carriageway of the road shortly after 1pm yesterday (Thursday July 25).
The lorry crossed the central reservation and turned over, blocking the westbound carriageway while the eastbound carriageway had to be closed because of the damage to the barrier and the wreckage of the Vauxhall.
It is believed that the car was travelling slowly, possibly with its hazard warning lights flashing, about half a mile east of the Southwick Tunnel when it was hit.
The 49-year-old male driver of the Vauxhall, from Hassocks, suffered leg and chest injuries and was taken to Royal Sussex County Hospital in Brighton for treatment.
The 79-year-old male passenger of the car, also from Hassocks, suffered what were at first thought to be serious head injuries and was flown to Southampton General Hospital. Those injuries are now believed to be relatively minor.
The 44-year-old male driver of the lorry was taken to Royal Sussex County Hospital for treatment for minor injuries.
After his release from hospital he was arrested on suspicion of causing serious injury through dangerous driving.
The A27 was closed between Hangleton and Holmbush for more than six hours and further repair work to the central barriers meant it had to be closed again later that evening.
Sergeant Tony Crisp, of Arundel Road Policing Unit, said: “Motorists faced many hours of delays because of the collision and I am grateful for all the patience they showed.
“Although the incident itself was over relatively quickly, the A27 was left too dangerous to use until the vehicles involved had been removed and the barriers made safe.
“I am still keen to speak to any drivers who saw the collision take place or who saw either of the vehicles involved in the minutes beforehand.”
Anyone with information should call 101 quoting serial 813 of 25 July or the independent charity Crimestoppers anonymously on 0800 555111.