I've often noticed that when there are traffic lights at a junction, but the lights are not working, the traffic from both directions seems to flow much better!
I can remember the London Road/Honor Oak Road junction before traffic lights were installed and I don't recall seeing the tailbacks that there are now.
Granted, the density of traffic is probably much higher now, but I wonder whether things would flow better if the lights were removed again or perhaps they were replaced by a mini roundabout?