At its peak in the second century, the Roman Empire dominated nearly two million square miles of the world. As with most such grand achievements, it couldn’t have happened without the development of certain technologies. The long reach of the Eternal City was made possible in large part by the humble technology of the road — or at least it looks like a humble technology here in the twenty-first century. Roads existed before the Roman Empire, of course, but the Romans built them to new standards of length, capacity, and durability. How they did it so gets explained in the short video above.
On a representative stretch of Roman-road-to be, says the narrator, a “wide area would be deforested.” Then “the topsoil would be removed until a solid base was found.” Atop that base, workers laid down curbs at the width determined by the road plan, then filled the gap between them with a foundation of large stones.
Atop the large stones went a layer of smaller stones mixed with fine aggregates, and finally the gravel, sand, and clay that made up the surface. All of this was accomplished with the old-fashioned power of man and animal, using tipper carts to pour out the materials and other tools to spread and compact them.
Roman road-builders didn’t just use any old rocks and dirt, but “carefully selected materials of the highest quality” — including formidably long-lasting Roman concrete, the secrets of whose sturdiness have only been fully understood in the past decade. In another ingenious design choice recently discovered, “ditches were placed to prevent access to the road from unauthorized vehicles,” as well as to widen the peripheral view of the road’s users. In the video just above, civil-engineering specialist Isaac Moreno Gallo takes a closer look at a section of a real Roman road being excavated where it will intersect with a modern highway under construction. The new road will surely stand for a long time to come — but will it inspire fascination a couple millennia from now?
The Roman Roads and Bridges You Can Still Travel Today
How to Make Roman Concrete, One of Human Civilization’s Longest-Lasting Building Materials
The First Transit Map: a Close Look at the Subway-Style Tabula Peutingeriana of the 5th-Century Roman Empire
How Did Roman Aqueducts Work?: The Most Impressive Achievement of Ancient Rome’s Infrastructure, Explained
The Roads of Ancient Rome Visualized in the Style of Modern Subway Maps
The Roman Roads of Britain Visualized as a Subway Map
Based in Seoul, Colin Marshall writes and broadcasts on cities, language, and culture. His projects include the Substack newsletter Books on Cities, the book The Stateless City: a Walk through 21st-Century Los Angeles and the video series The City in Cinema. Follow him on Twitter at @colinmarshall or on Facebook.