Inca Empire road network

Timeline

1. 1451–1455Andean crest trunk road (northern section) · Northern PeruIn the early 15th century 50s the Sapa Inca Pachacuti launched large-scale conquests of Chinchaysuyu (the northwestern quarter), with road works laid alongside the armies. Work crews organized under the mit'a corvée system paved the roads with stone slabs over the rugged highland terrain, generally 1 to 4 meters wide, cut steps on steep slopes, and built suspension bridges to cross deep gorges and rapids.
2. 1456–1460Empire-wide road relay station system · Andean regionAs territorial expansion stabilized, Pachacuti focused on perfecting the road infrastructure: tambos (relay stations) were set up every 20 to 30 km, providing storage, lodging, and military supplies; chasqui huts were placed every 2 km, where specially trained relay messengers passed quipus (knotted records) and physical messages in relay, covering about 240 km per day—far exceeding the communication speed of major Eurasian civilizations of the same period.