In what ways is the road an important symbol in the novel? (what can the road represent?)Cormac McCarthy's "The Road"

In Cormac McCarthy's Southern Gothic and Naturalistic "The Road," the father and his boy travel the road to the ocean.  The road is what gives them direction, what gives them purpose, what affords them the opportunity for a reason to survive:  they must keep traversing the road.  It is the life-driving source in a world devastated and eradicated. That the road is central to the father and son's existences is evidenced in this passage from page 261:

He got up and walked out to the road.  The black shape of it running from dark to dark.  Then a distant low rumble...A sound without cognate and without description....He walked out into the road and stood.  The silence...At a crossroads a ground set with dolmen stones where the spoken bones of oracles lay moldering....

Throughout the novel, the father has flashbacks and he and the boy have misgivings about their survival, but the road ahead takes on a spiritual meaning and gives them some direction to their lives. But, unlike a road of many novels, such as the road to California that takes the Joads to new life and new hope in "The Grapes of Wrath"--albeit fraught with dangers along the way--the road of McCarthy's narrative can only be traveled in the night by the father and the boy, for Death lies in wait for them.  Finally, in a naturalistic denouement, the father must succumb to implacable Death.