"He was in a car transporting some furniture, I don't know what kind of car presumably a ute or something, and the chair fell off the back of the vehicle so the occupants of the car dropped one of the members off and they were going to do a circuit and come back to pick him up.
"He was there waiting and decided he would have a seat while waiting."
Mr Edwards said the man was removed from the bridge a short time afterwards by police.
He said he was unsure if the man or his friends had been given any tickets.
"They are committing an offense by blocking the road. He was blocking the road and my understanding, although I haven't seen the image, was making little attempt to move."
He said the incident occurred just after 1pm.
The image was uploaded three hours ago on photo sharing site Imgur. It has so far been viewed almost 1000 times.