Fiori takes civil engineers and students to Peru to study the Great Inca Road.
Photo: Christine Fiori
Fiori takes civil engineers and students to Peru to study the Great Inca Road.


The ancient Inca built a complex system of roads that span some 20,000 miles and range in altitude from sea level to 14,000 feet, all without the benefit of special tools or even a formal writing system.

And yet “they were incredible hydrologists,” says Christine Fiori, a civil engineering professor leading a $90,000 research study for the National Science Foundation and the Smithsonian’s National Museum of the American Indian. The study is helping engineers understand sustainable design practices—a hot topic in building construction—in the engineering of civil infrastructure such as roads and bridges.

Fiori, a geotechnical engineer and director of undergraduate programs at Blacksburg, Va.-based Virginia Polytechnic Institute and State University, says she was inspired by a trip to Peru, where she compared the area’s modern Interoceanic Highway to the 700-year-old Great Inca Road.

“We were looking at the differences between this ancient road that was still being used and this other one that was crumbling,” she says. Last summer, Fiori took researchers and students to Peru and plans another expedition this summer.

Results of the study are slated for display at the Smithsonian for a special exhibit on Inca culture planned in 2013. Meanwhile, Fiori’s team is continually broadcasting field reports back to the Smithsonian via satellite, giving museum visitors a unique learning experience. “It feels like a face-to-face discussion,” says Barbara S. Mogel, exhibit manager.

The Inca built highly complex roads, bridges and buildings that have lasted for centuries by taking note of how water moves naturally and accommodating it. “They built for the 100-year flood,” Fiori says. “We don’t do that. We look at hydrologic models.” What’s more, the Great Inca Road is still largely in use today, prompting Fiori and other researchers to ask why modern roads don’t last as long.

The Inca benefited from a public “labor tax” bordering on slavery. But they also used environmentally sensitive engineering techniques and local materials—some of the hallmarks of today’s green movement.