The A259 at Newhaven has been closed following a collision between a man and a car at 2.30pm today (Tuesday February 17).
Police said the man was being assessed at the scene by paramedics.
The road has been closed between the McDonald’s roundabout and the flyover.
An ambulance spokesman said: “A man in his 20s suffered a head injury.
“He has recently left the scene and has been taken to the Royal Sussex County Hospital in Brighton as a priority.”