Any ideas how to keep people from driving on my lawn?

[Sillyoldman]

It does not happen too often. I live down a private dead end dirt road. I'm the last house. There is a turn-a-round prior to my property that trucks back into to turn around. Every now and then some dumba$$ drives on my lawn. I've also caught the mailman & DHL driver (Yep DHL driver, twice) driving on the grass. Last night I noticed it happened again. The problem is that under the grass is my drain field. Now I feel I need to put up a barrier to keep cars off. The lawn is about 120' long. I'd like to find some 3" rope and build a rope fence. I can't find any surplus rope. Maybe I'm not looking in the right place. I understand ship mooring lines have a short life and need replacement frequently. Anyone know where to get this stuff? Any other ideas? I've thought about boulders, but that would require a tractor and dump truck. A lot of nasty ideas have crossed my mind too, but thats not an option.


Decided to toss in a pic of the pond I built. Almost ready for some fish.