A nice little email from "KB" turns up to look at this pair of cars, TG05TOM and YE56YUG that apparently double park regularly on Elton Road, Bishopston. They aren't interfering with left-turning cars, because it's a one way road: no left turn.
The apparent problem here is that little buildout you see in the right of the picture. It is not, as one might think, a pedestrian crossing. It's a contraflow for bikes, and with the two cars parked here, there is no way to enter the contraflow. This may be a bit inconvenient.
But where does the contraflow go? Gloucester Road. At the infamous Gloucester Road/Zetland Road junction where the police now come out and ticket cyclists who cycle on the pavement and through red lights. And how does this cycle contraflow end? With a pavement route followed by a green light to cycle while the pedestrians get the little man. If you could cycle down here, you would end up doing both the activities that the police were stamping down on. These cars are parking where they are for the sake of the cyclists, not themselves.