good evening: Interesting point. I have been thinking along the same lines, but the fact that they were staking land along the proposed route, may answer your question.
In Mexico, permission must be asked for. I had a claim surrounding another's property. (Hate people that do that ) He had no access except over my land. He asked me what did I want for permission to cross over my land. He was a very nice gentleman, so I simply told him that he had unlimited access over the present road at no cost to him except to keep the road maintained. ok Ok so i am a softie and a lousy business man. snifff.
His family still sends me Christmas cards
Don Jose de La Mancha