I believe Liverpool are experimenting with abolishing their bus-lanes. Presumably they won't allow parking in the freed-up lane.
---------- Post added 02-01-2015 at 16:55 ----------
As for Eccy Road, I suspect replacing Hunters Bar roundabout with a simple crossroads would help (but would look crap, admittedly). I don't claim to be an expert either, but I get the impression that a lot of bottlenecks in Sheffield are roundabouts. They just don't give the same throughput of traffic as a simple junction. The fact that most of them have traffic lights on the approaches suggests that the planners know this.