Okay, he'll say "which road goes to your village?". He would then take the route the person pointed to. The truthful peson, would point to his village, the truth village, right? Also, the liar would point to the truth village, the same village because he can't tell the truth. So, if the traveller wants to go the truth village, he knows which road to take. Then, if he wants to take the lie village, he would take that. But, why would anyone want to go there? Next, he should make signs saying "Truth Village" and "Lie Village: Don't go here!"
Anyway, do you get it?
Hopefully this helps!!!!!