Here are my assumptions based on the riddle

1.) you can only ask one question which you can pose to both at once.
2.) you have no idea which guy is the liar or the truth teller. If you know who is the truth teller and the liar it is easier.

Arbitrarily choose a road and ask them both: " If I asked you does this road lead me home, would you say yes?" - If it is the way home, the truth guy will obviously say yes. The liar will also be forced to say yes; this is because this question is something the liar would normally answer no to, but you've also then asked "would be say yes" - so here he cannot say no because then he would be honest about being a liar and since he cannot be honest he would be forced to answer yes.

Conversely if it were not the right road, the truth guy would say no, and in the same fashion the liar would be forced to say no since he would normally lie and say the wrong way is the right way, but because he cannot admit that he would do that he must lie about the fact that he would lie, and that would lead to a no answer to the death road.

This way you either get double yes or double no and then chose the right road accordingly.