In The Road by Cormac McCarthy, the book focuses on the powers of destruction. The author seems to suggest that evil has the upper hand at the moment.
“The Road” keeps pace with the most enterprising doomsayers as death and desperation manifest themselves on every page. And in a perverse miracle it yields one last calamity when it seems that things cannot possibly get worse."
"father and son encounter all manner of perils. The weather is bitter, the landscape colorless, the threat of starvation imminent. There is also the occasional interloper or ominous relic, since the road is not entirely abandoned."
Remember that a road, when used in literature, often symbolizes choices more than anything else. It's the choice of which road we take which ultimately leads to where we end. In The Road, the choice of paths taken is the difference between the path of good, and the path of evil. Good being sacrificing for others (selflessness) for the greater good, and following the moral code. There is also consequently a road of evil which is selfishness and immorality. Often writers use Evil as a stronger power so that when the character chooses good, it's a fight.