Police are seeking witnesses to a two-car collision on the A21 at Hurst Green.
The incident happened at around 4.15pm on Sunday (June 17) and which left two women with serious injuries.
Police said the vehicles involved were a white Hyundai travelling south, driven by a 64-year-old woman from Hurst Green, and a black Audi travelling north, driven by a 54-year-old man from London.
The Hyundai driver and a 74-year-old woman from Staplehurst, Kent, who was a front seat passenger in the same car, were both taken by ambulance to the Royal Sussex County Hospital, Brighton, for treatment to fractures.
Police said the Audi driver sustained bruising and whiplash and was treated at the Conquest Hospital, St Leonards.
The collision, which happpened some 500 metres north of the A21’s junction with the A229 Merriments Lane, caused traffic tailbacks over several miles while the incident was being dealt with.
Diversions had to be set up for motorists until the A21 was reopened at 7pm.
PC Gary Douglas, of the Polegate road policing unit, said: “We’re keen to speak to anyone who may have information which could help our enquiries into the incident.
“We would also like to thank drivers whose journeys were delayed or disrupted by this crash for their patience and understanding.”
Anyone who saw what happened, who has relevant dash-cam footage or who noticed either vehicle being driven shortly before the collision is asked to report details online to Sussex Police or phone police on 101, quoting serial 813 of 17/06.