It occurred on Otley Road, near the junction with Manor Drive, just after 5.20pm on Tuesday 26 July 2011 and involved a white Honda Civic and a red and silver Peugeot Speedfight moped.
At the time of the collision the moped was heading into Harrogate and the car was reversing into the road.
The 19-year-old local man riding the moped, was taken to Harrogate District Hospital with a broken leg.
The 46-year-old Harrogate man driving the Honda was not injured.
Traffic Constable Dave Seavers, of the force’s Roads Policing Group, said: “I am particularly keen to speak with a jogger who briefly stopped at the scene following the collision, as I believe they may have vital information about the collision.
“I urge them, or anyone else who witnessed the incident to come forward as a matter of urgency.”
If you can assist with this investigation please contact TC Dave Seavers on 0845 60 60 24 7 quoting reference number 12110124551.