Putting Up No Parking Signs & Laying Demarkation Lines

[davidjohndesigns]

We live at the very last house on a Cul de Sac, have done for the past 3 years, our deeds show that we own the entire plot, even though it looks like a bit of road, this bit of road actually forms part of our drive, unfortunately it also butts up to or neighbour immediately opposite, he has a parking space for 1 vehicle that is accessed by crossing our plot/bit of road, we allow him clear access over our land so he can park.
However he and his family insist on parking on our plot rather than their own, and infuriatingly when we complain, they move their cars 2 feet onto their own space and leave the rest of their car on our land, when we tackle them about this they say they are not causing a problem because as far as they can see we can get our cars in and out of our drive without difficulty, which actually we cant , we have to reverse in using multiple point turning etc, but that is not the point, the land is ours, and don't we have a right to keep it clear for our own vehicles or use?
Can we put up signs indicating the land is private and not a public road or car park, and can we put down white line hatching to indicate a no parking zonee

[johnk]

Who maintains this piece of road?

[johnk]

Who maintains this piece of road