Officers are appealing for witnesses and dash cam footage after a cyclist was knocked over at Cooksbridge, near Lewes.
It happened on Saturday (Oct 1) between and 2pm and 2.15pm in Beechwood Lane in the village.
A woman was struck by the wing mirror of a silver or grey van or pick-up truck, which had been driving too close to her.
She was knocked from her bike, sustaining a serious but not life-threatening injury.
PC Martyn Quick, from the Roads Policing Unit (RPU), investigating, said:
“We are appealing to identify the driver of the grey or silver van involved in this collision.
“The driver did not stop at the scene, and we believe the area was busy with other motorists and road users at the time because the level crossing nearby was down.
“Anyone with relevant CCTV or dashcam footage of the vehicle matching the description in the area at the time is asked to come forward.”
Information can be reported to Sussex Police online, on 101, or by emailing: [email protected] and quote serial 1123 of October 1.