One piece of tweaking to the phasing which might help would be to allow traffic heading north-east from the A316 time to completely clear the roundabout. When the lights on the A316 change to red there should be more time allowed before the lights on the western side of the roundabout change to red, and perhaps allow the lights on the northern side to change to green slightly earlier. All traffic could then complete the negotiation of the roundabout from the A316 along the A4 eastbound or Dorchester Grove/Devonshire Road in one move.
At the moment there are always some vehicles which are "trapped" on the roundabout because the western lights change to red at about the same time as the A316 lights. If too many try to rush the lights it creates a jam and subsequent tailbacks on the A4 because of blocked lanes. |