Since wheeled vehicles were unknown to the Inca, the surfaces of the Inca Road did not need to be smooth and flat. Some of the roadways were paved with stone, but most were natural dirt pathways between 1-4 meters in width.
The road system was well integrated into an extensive drainage system, which included constructed agricultural terraces, subterranean cave reservoirs, retaining walls, and a centralized main drainage separating urban from rural drainage systems. Machu Picchu alone had 129 constructed drain outlets.
Not all of the travel on the road was necessary. Recent studies of cut andesite stone blocks at Paquishapa originated near Cuzco, a distance of 1600 kilometers. Each of these massive objects (each weighing up to 700 kilograms) were hauled by hand through the Andes mountains along the Inca Road. Researcher Dennis Ogburn believes this feat was an example of non-necessary make-work, imposed by the Inca on subject peoples to prove their control.
Sources and Further Information
Inca Empire Study Guide
The Inca Road System
Hyslop, John. 1984. The Inka Road System. Academic Press: New York.
McEwan, Gordon F. 2006 The Incas: New Perspectives. Santa Barbara: ABC-CLIO.
Ogburn, Dennis E. 2004 Evidence for Long-Distance Transportation of Building Stones in the Inka Empire, from Cuzco, Peru to Saraguro, Ecuador. Latin American Antiquity 15(4):419-439.
Wright, Kenneth R., Alfredo Valencia Zegarra, and William L. Lorah 1999 Ancient Machu Picchu Drainage Engineering. Journal of Irrigation and Drainage Engineering 125(6):360-369.
