yah the fences are a terrible idea. They might make sense if people obeyed traffic laws to begin with, but with everyone used to doing whatever they want, the barriers only make things worse. After one intersection gets jammed and cars cannot get across, a lane on each side of the traffic light becomes empty (ie going north one way and going south the other). Cars backed up going the opposite direction then find any openings further up or down and cross over and start going the wrong way to pass the stopped traffic. This happened while we were walking. Then the intersection jam broke up and the cars started flying up the road, only to be met by the cars headed the wrong way. With the barriers there they had no way of getting back. Quite the entertaining/dangerous situation.
Wuhan traffic sucks at rush hour, and the fact that subway construction above ground takes up all but one lane in some places doesn't help. Nor does the fact that the tunneling machine was prioritized to build the Hangzhou subway, and so the Wuhan Bucket Brigade won't finish the lines here until 2012. But seriously after driving by and seeing some of the subway construction sites, it wouldn't surprise me if they are digging by hand.