A head-on crash at Warrimoo on Wednesday evening is under investigation, with police appealing for witnesses.
Police allege that a 26-year-old Warrimoo man drove a blue Toyota Prius on the incorrect side of the road in a westerly direction along Railway Parade, Warrimoo about 6.30pm on January 22.
"In doing so, the blue Toyota Prius collided with a blue Yamaha motorcycle that was being ridden by a 20-year-old male from Faulconbridge," said Blue Mountains Police Detective Inspector Scott McAlpine.
The motorcyclist suffered severe injuries and was taken to Nepean Hospital. "He is still undergoing treatment and is in a stable condition," Det Insp McAlpine said.
Police are appealing for any witnesses to the crash and any drivers who may have dash cam footage of the collision to contact Blue Mountains detectives at Springwood Police Station on 4751 0299 or Crime Stoppers on 1800 333 000.