These people are driving up and down your private road? Are they also residents of the private road? If not, I would be considering a gate and appropriate signage. I totally understand the points you've made but surely there comes a limit to what one must tolerate of those who cannot see beyond what directly influences them.
Dust Removal
We live on a dirt road and thanks to certain neighbors who refuse to slow down, we are constantly wiping dust off horizontal surfaces in our house. I'm sure there must be dust inside my components but am not sure of the best way to deal with it.
Blow it out w/ compressed air?
Use a vacuum?