McCarthy is one of my favorite authors, and his style is both very unique and quite consistent. He relies on vivid imagery, in The Road especially, to construct a portrait in the reader's mind that is filled with near hopelessness. Consider the double tragedy to start the novel, the nondescript apocalyptic disaster that is slowly, simultaneously exterminating mankind and its humanity at the same time, and the grim suicide of his wife, leaving the man and his son alone.
Consider the mission they are on, both simple and hopeless in its own right: to make it to the ocean. To follow the coastline south to where there are perhaps, still some sane people left, or some food to survive on. Even the reader can't buy into the plan as something to focus on in the book. McCarthy's tone, introduction and setting constantly reminds the reader not to look towards the end, towards the resolution. It slowly convinces us to accept the reality that there is no solution, no hope, and daily survival is the only thing that's relevant and possible. Survive to the next page, the next chapter, and you begin to understand.
The style of the book is similar in some ways to other works by McCarthy, but also simpler and more direct. The descriptions of the road and the ash and the world in which the man and boy live are powerfully simple.
The beginning sets the tone by building the image of this very grey and cold world, one in which all hope for the future rests on some very thin assumptions and underpinnings about there being "good guys" and any possibility of survival. From the beginning you also get a sense of the amazing determination of the father and the importance in his world of finding his son a better place to be and live.