The driver of a car in collision with a cyclist in Wakefield fled the scene and left the rider with serious injuries.
Police are now appealing for anyone with information and particularly dash-cam footage to get in touch.
The 22-year-old cyclist sustained serious injuries and was taken to hospital for treatment following the incident on Balne Lane under the railway bridge at around 3.40pm on Sunday.
It is thought that the car involved was possibly a blue Vauxhall but the driver didn't remain at the scene.
Police are appealing for anyone who witnessed the collision to get in touch with the eastern area Safer Roads Team on 101 or by using the West Yorkshire Police live chat facility, quoting log 1415 of 02/09.