Conceivably, under the old system, the traffic could have been kept moving, albeit with difficulty.  The weakness of this new design is that whereas before traffic all flowed evenly in one direction, there is now built-in hold-ups due to the extra sets of traffic light plus additional right and left turns around what was a relatively free flowing system. Do the vastly widened pavements carry as many pedestrians as the Strand and Trafalgar Square?  Of course not!  This has been achieved by narrowing the main road around the town centre, and in addition ,supposedly justifying a 20 mph speed limit, which only aggravates congestion.  Furthermore these pavements are so wide that they have prevented the inclusion of filter lanes that would have enabled drivers to avoid stopping at traffic lights,generally improved traffic flow, in turn reducing emissions. This highly expensive (£?? million) scheme (scam?) is purely cosmetic seemingly designed to restrict, delay and frustrate drivers, with dubious benefits for pedestrians and cyclists. 

The so-called "concrete collar"remains. Had the courage and imagination been taken to compulsorily purchase some of the adjacent land to the ring road scheme to separate through traffic from local traffic would have achieved a freer traffic flow.