A 20-year-old Isaacs man has been charged with drug driving after allegedly colliding with a motorcyclist on Thursday night and fleeing the scene.

The motorcyclist was taken to hospital with serious injuries.

Police say that about 7.40pm there was a collision between a Harley Davidson motorcycle and Toyota sedan at the intersection of Yamba Drive and Julia Flynn Ave, Isaacs.

Police say the driver fled the scene, but was located by a member of the public in Mawson and returned him to the collision scene. He tested positive for driving with drugs in his system and he was taken into custody.

The driver faces charges of negligent driving causing actual bodily harm, drug driving and failing to stop and give assistance.