Blocking juction on motorway roundabout

During traffic lights changing of signal, cars on the roundabout of junction 7 M27 block the junction of Charles watts way A334 and cause unnecessary traffic build up. we need a Yellow box junctions in place to keep the junction clear for through-traffic to avoid traffic jams!!.also the traffic lights don't change frequent enough on junction of Charles watts way A334 and stay green to long on roundabout causing traffic to build up down Charles watts way to Wildern Lane, even when there is no traffic on roundabout!..