Single lane slip road turned into two lane

Good Afternoon, I live in Boyatt Wood and have commuted via the M3 to Basingstoke Monday – Friday for the past 20+ years. As the roads are getting busier, I have noticed that the Junction 12 southbound slipway (southbound) is getting more and more busier with traffic backing up nearly to the motorway most nights during rush hour. This is mainly due to traffic turning left at the roundabout towards Chandlers Ford (Winchester Road). The slip road currently is wide enough for two lanes but has no signs or road markings, as the traffic backs up on the left hand side of the sliproad drivers take it upon themselves and at risks to others to drive down the righthand side of the sliproad to pass all the queuing cars ( normally at great speed due to just exiting the motorway). Has anybody thought to turn the sliproad into two lanes so that the left lane goes towards Chandlers Ford and the right lane goes toward Eastleigh or right on the roundabout. My simple understanding thinks that this would be a reasonably cheap answer to helping clear traffic on the sliproad. There is even a plot of land on the left side of the roundabout that could even turn into a merging lane onto Winchester road to help speed up clearing the traffic heading into Chandlers Ford. Regards