Expedition on the Inca Road

Feb 27, 2014

The infrastructure in this country is a source of concern, as many aging roads and bridges need repair.  A construction specialist at Virginia Tech is studying a seven hundred year old road in South America to see what modern engineers can learn about building roads that last. 

The Inca Road runs from Ecuador to Chile; through rainforests, deserts, and over mountains.  In some places it’s just a path through the woods, like you might see on the Appalachian Trail.  In other places, feats of Inca engineering stand as testaments to their knowledge of construction.

Christine Fiori, associate dean of the Myers Lawson School of Construction at Virginia Tech, has been studying the Inca Road for years.“They understood the forces of nature and they engineered with it instead of against it “

The road is still in use today.  It’s had help – having been maintained by villagers who live along it, all these hundreds of years.  But Fiori says the way Inca Engineers handled the challenges of nature holds lessons for modern road builders.

“Take I-81 as an example. We wanted to widen the road so we just blasted away the rock. And that’s a practicality in our environment.  The Inca looked at alternate routes versus destroying nature.”

But Fiori says, when they had to, the Inca also did a version of blasting.  “They would heat the rock up with a fire and then throw cold water on it and watch it crack or they would pound wooden stakes into cracks within the rock, wet it and let the wood expand and crack the rock. They actually did some excavations in some areas --They were just amazing in how they observed natural phenomena and used it in a way that was forwarding their engineering goal or engineering design.”

Fiori did the first detailed engineering study of the Inca Road. She’s trekked alongside archeologists and historians and got her own interdisciplinary education about the meaning of the road in Inca civilization.

“They used the road to connect different parts so f the empire and then  the road  was also, to the Inca, almost a language because they were conquering different tribes and moving as they expanded their empire and there really wasn’t one unified language so they  generally what you saw, how you walked along the road, what views you saw, by the road. So it was a means of communication, it was a means of pilgrimage, and it was also, for practical purposes a means of getting goods to various markets and connecting different villages as well as moving troops.”

The Inca road is a vast network that branches off in many directions.  And like roads that lead on to other roads, Fiori’s engineering study too, raised still more questions.

"One of our big questions that still have not --we’ve come up with a lot of crazy ideas but we haven’t been able to figure out; how did they survey so well? What did they use to get that straight line? That’s one of the things that we were trying to see. OK you have no written language, so how’d you build?"

The Discovery Channel is asking that same question in a segment on the road that will feature Fiori in a program called, “Strip the City” that will air in March. Most of their topics are modern structures, but the Inca road made the cut.

“For me that’s the ultimate in sustainability.  That's what people should take away from this and they worked in harmony with it and I believe firmly that if we as engineers and constructors go back to those ways we can again engineer things can go build things for the century instead of or the decade.”