Police are appealing for witnesses to a collision on Devonshire Road in Bexhill at the weekend, which was attended by the air ambulance.
A pedestrian was seriously injured in the crash, which saw the 33-year-old driver of a silver Vauxhall Astra arrested on suspicion of causing serious injury by dangerous driving and driving while over the specified limit of drugs.
It happened on Sunday, 3 August around 4:40pm at the crossing on Devonshire Road.
The Kent and Sussex Air Ambulance was called to the scene which landed at the De La Warr Pavilion.
The pedestrian remains in hospital with serious injuries.
The suspect has been released on conditional bail while the investigation continues.
Anyone who witnessed what happened or with relevant information is asked to come forward.
Information can be reported to Sussex Police online or by dialling 101, quoting serial 990 of 03/08.
