Parking in residential area

In Paddock Close there is a turning circle of which many personal drives come off of. Frequently there are cars parked in the turning circle and this makes it obsolete and obstructed. I know that at least one house needs 24 hour access and that the parked cars make this difficult. What can be done to solve this issue?

Furthermore each house has a garage and a driveway capable of keeping a total of two cars on their land, a couple of houses even have enough room for three cars in total. They tend to park specifically in front of number 9, although we have spoken to the residents there and they don't have anything to do with those cars. They did comment that the cars when parked there were an eyesore and made it difficult to use their driveway. The issue has been present for as long as I can remember since living here