Planners love this stuff
In my area there are a few schemes on the go that are the same. On my (former) route to work there's an insanely busy roundabout that's having one side removed, turning it into a festival of traffic lights with lots of fancy paving. This is in aid of making the thing more 'pedestrian friendly', despite the fact that 2 sides are already roofed over, with pedestrians going over the top without a care in the world.
The council selling off the land that was formerly one side of the roundabout might have more to do with the motivation for the scheme.