A 'possible medical episode' has led to a collision on the A259 near a garden centre in Angmering, according to Sussex Police.
Sussex Police said the collision was reported to them at 12.15pm, 'involving two cars' on the Roundstone Bypass, near Haskins Garden Centre, 'one of which has gone on to collide with a tree'.
The spokesman described it as a 'possible medical episode'.
The ambulance service said the driver of the car that had collided with the tree had got out of the vehicle by himself and was 'conscious, up and about at the scene'.
Having checked the man at the scene, he was taken to Worthing Hospital by ambulance for further checks.
There were no other reported injuries.