It's pretty much a rule that whenever you have a road in a work of art, it's a symbol. Ever read Cormac McCarthy's The Road? Duh. And let's not forget On the Road by Kerouac and "The Road Not Taken" by Frost.
The Rascal Flatts song "Life is a Highway" explains the symbol right in the title. And then there's A Canticle, which joins this group of artistic works, all thanks to the road leading to the Leibowitz Abbey.
This road appears in all three eras:
- In Fiat Homo, the road is one "from nowhere, leading nowhere, in terms of the modes of travel in those times" (1.5).
- In Fiat Lux, travel to the abbey becomes far more doable, minus the occasional road hazard or bandit.
- Finally in Fiat Voluntas Tua, the road now separates the various buildings of the abbey. Crossing it is dangerous because the automated vehicles might run you down. As Brother Joshua puts it, it is "like crossing an eon" (24.185).
This road doesn't represent life or a state of mind like many road symbols. Instead, it symbolizes the progress of humanity, almost serving as a physical timeline for it.
Francis first meets the wanderer while walking over the road, coming into view like something out of the past. Then the road grows to accommodate many more travelers, and the town of Sanly Bowitz. It eventually becomes a technological marvel, but like all technology in the novel, this marvel is dangerous.
As humanity progresses, the road becomes larger and easier to travel on, but that travel also becomes more and more treacherous. Francis only had to worry about the occasional stranger, but Thon Taddeo had to concern himself with an entire tribe of rough-and-tumble tribal warriors.
In the final era, automated vehicles threaten to mow down any passerby not quick enough to scurry out of harm's way.
So the road simultaneously helps and hurts people, like humanity's scientific progress in general. In the end, A Canticle seems to suggest that if life is a highway, and you're going to ride it all night long—whether you want to or not.