How funny -- poles? I've never seen that. So my idea may not be suitable. My thought would be something like this, which is meant to be a solution for excess stormwater draining into the street. Probably not applicable to your area, but I think it's pretty.

This post was edited by Violet.West on Tue, Jun 17, 14 at 18:16

I would give up on the idea that a bed of liriope will protect your lawn. People will just as happily run over it, and there is a much longer recovery time.

The device you need is bollards, which are usually some form of short, fat post. But they only need to be tall enough to threaten harm to a vehicle. If it's only cars, 8" height of beefy material ought to do it. Semis would need something more substantial. The picture is an example of concrete ball bollards. You could DIY a similar solution out of spent bowling balls for a lot less cost. Or use something entirely different and be a trendsetter. (But it must be well anchored.)

{{gwi:36961}}

Do you know where your property line is located? The road probably has a right of way that includes some of the grassy area. Don't be installing any bollards in the right of way unless you have permission from the local municipality.

Would a hedge work in your case?
Mike