A cyclist, 63, was cycling in the direction of Blackpool when he collided into a parked Renault Clio on Blackpool Road just before 9am on Monday (May 18).
He was taken to Royal Preston Hospital where he is being treated for serious head and neck injuries.
Police would like to speak to anyone who saw the incident, or has dash cam footage of the cyclist and car leading up to the collision.
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A spokesperson for Lancashire Police said: "We are appealing for information after a cyclist was involved in a collision with a stationary car on Blackpool Road, Preston."
Anyone with any information is asked to contact police by calling 101 quoting log number 0275 of May 18.