How to make an impassable road?

[Quintaxel]

It's possible that this has already been discussed on the forum. I searched but could not find an answer to the question;
 "How to make an impassable road?" or maybe you could put the question in another way. "How can I make a river with the texture of a path or road?"
Why would I need an impassable road? Well  need to make some areas of a map impassable for vehicles or squads. I know this can be done by selecting terrain or objects but this is not flexible enough for what I have in mind.

[Mat]

gagarin made a complete set of impassable roads, check his thread, he posted it not long ago

[Scyooff]

Here exactly 

[Quintaxel]

Thanks guys. I'll check it out.