Any implications if I put a few polite rocks on the grass verge outside my house ?

I used to pass by a house which had a barrell with two legs sticking out of it.
It got a lot of passing interest but probably wouldn't work in this case ......I would guess
 
Some people round the corner from me sorted this by planting very pretty and visible flower arrangements on the grass verge outside to make people think twice about driving or parking on it. Some of them are more demure but one of them is more like Day of the Triffids, so its clear you cannot park there.
 
This may be of interest to the original post. A neighbour had similar problems where cars, rather than stop to let another car pass, would drive up and sometimes drive along the grass verge. He maintains the verge and it was becoming unsightly with wheel tracks, and ruts from heavy vans, etc.
He simply stopped mowing about a foot wide strip on the outside edge of the grassy area. When the grass got long, drivers stopped driving into the verge because they couldn't see that there were no rocks, obstacles, etc. Another option might be to plant low growing hardy plants along the edge, e.g. heathers. May have a similar influence on drivers