Blocking driveway

Everyday a different car is blocking access to our driveway. We have reported this before. There is a dropped kerb outside the property but because of the tree people think it is okay to park there. We have a van that we need to get on the drive and it is a difficult job to do with a car right on the middle of our driveway. We are out all hours of the day and night due to shift work as a paramedic. It is never acceptable for our drive to be blocked especially due to it being a dropped kerb. We have left countless polite notes on peoples cars to advise them not to park over the dropped kerb but each day a different car is deciding to park there presumably because they think it is okay because there is a tree there and where people have parked before the mud has sunk down which means they can see the kerb on the pavement side and are ignoring the fact the the kerb is level with the road. It is getting frustrating for us as homeowners are are unsure how to stop this ourselves. The mud needs to be replaced with a stronger wearing material so people can see that the kerb is dropped or the tree needs to be relocated/removed so people aren’t gravitated to parking there. This has been a continuous problem since we moved into the house in May last year (2023).