Roadways were the lifeblood of Ancient Rome. Over the course of 700 years, the Romans built more than 55,000 miles of paved highways throughout Europe—enough to encircle the globe. These engineering marvels ensured the swift movement of goods, soldiers and information across the Empire, and played a crucial role in tightening Rome’s grasp on the Mediterranean Basin. Explore eight reasons why this remarkable transit system helped unite the ancient world.
The first major Roman road—the famed Appian Way, or “queen of the roads”—was constructed in 312 B.C. to serve as a supply route between republican Rome and its allies in Capua during the Second Samnite War. From then on, road systems often sprang from Roman conquest. As the legions blazed a trail through Europe, the Romans built new highways to link captured cities with Rome and establish them as colonies. These routes ensured that the Roman military could out-pace and out-maneuver its enemies, but they also aided in the everyday maintenance of the Empire. Reduced travel time and marching fatigue allowed the fleet-footed legions to move as quickly as 20 miles a day to respond to outside threats and internal uprisings. Even the most isolated parts of the Roman world could expect to be swiftly supplied or reinforced in the event of an emergency, lessening the need for large and costly garrison units at frontier outposts.
Since Roman roads were designed with speed of travel in mind, they often followed a remarkably straight trail across the countryside. Land surveyors, or “gromatici,” began the building process by using sighting poles to painstakingly chart the most direct route from one destination to another. The resulting roads often shot straight up steep hills, and small bridges and tunnels were built to ensure the path could traverse rivers or pass right through mountains. Even in instances where the road was forced to divert from its course, the Romans typically opted for sharp turns and switchbacks over sweeping curves to preserve their arrow-straight design. Britain’s Fosse Way, for example, only veered a few miles off course over its entire 180-mile distance.
Roman builders used whatever materials were at hand to construct their roads, but their design always employed multiple layers for durability and flatness. Crews began by digging shallow, three-foot trenches and erecting small retaining walls along either side of the proposed route. The bottom section of the road was usually made of leveled earth and mortar or sand topped with small stones. This was followed by foundation layers of crushed rocks or gravel cemented with lime mortar. Finally, the surface layer was constructed using neatly arranged blocks made from gravel, pebbles, iron ore or hardened volcanic lava. Roads were built with a crown and adjacent ditches to ensure easy water drainage, and in some rainy regions they were even nestled on raised berms known as “aggers” to prevent flooding.