Sussex Roads Police are seeking witnesses and video evidence after a multi-vehicle accident on the A26 near Ringmer.
The incident occurred around 4pm on Friday, August 25, close to the Esso station at Clayhill Services.
A 76-year-old East Grinstead woman, driving a Suzuki, suffered serious injuries and is currently in hospital in a critical condition.
Two individuals from the other vehicles experienced minor injuries.
The Roads Policing Unit is urging those with pertinent dashcam or CCTV footage from the vicinity to step forward.
For anyone with information or wanting to report, please reach out to Sussex Police online, dial 101, or email email@example.com referencing serial 1002 of 25/08 – Operation Emu.