Parking/Driving on grass verge outside houses on Amersham road

Cars keep driving on the grass verge outside my house, churning up the grass and making it look like a pigsty. I bought the house last year, and this keeps happening. It looks like the bollards that were there before have been taken down, which I assume were the council’s. There's a house up the road where people keep parking on the grass, turning it into a mud bath. I haven’t caught who’s doing it yet, but I will be approaching them once I find out who the culprit is. It looks awful, and I pay a lot of council tax. I don’t want to be looking at mud every day when I come home. It looks disgusting, and I think the council should consider putting the bollards back up.