It happened at around 6.40pm on Tuesday when two cyclists were waiting to cross Garstang Road in St Michaels at the bridge near to The Grapes pub.
One of the cyclist’s wheels was struck by a 4x4 type vehicle, possibly a red or maroon old style Land Rover Discovery, which dragged the cyclist across the road.
The rider, a 45 year old woman, suffered a broken arm and internal injuries and was taken to Royal Preston Hospital.
The vehicle did initially stop at the scene but left before the emergency services arrived.
PC Marc Saysell of the Road Policing Unit said: “The cyclist has been left with some nasty injuries as a result of this collision and enquiries are underway to trace the driver of the 4x4 which failed to stay at the scene of the accident.
“I would urge anyone who witnessed what happened, or anyone who has any information about the vehicle involved to come forward. Similarly, if the driver of the vehicle sees this appeal, I would appeal to them to come forward and make contact with us.”