The first roads were simple paths made by animals and followed by primitive man, in an attempt to broaden their horizons. Although all primitive societies had roads – either natural paths or straight roads made by cutting down trees and leveling the ground – the first real road workers were the Romans.
Through their meticulous nature and their engineering skills, they have turned road construction into a science. They built the first cobbled paths, often made of slabs laid over real masonry foundations, which has survived to this day.
It is estimated that the total length of roads built by the Romans between the third century BC. and the 4th century AD. is 80,000 km. The route of these roads is very judicious and there are many cases in which modern roads use sections of Roman roads.
The Romans built 29 main roads, generally for military purposes, starting radially from Rome, the first and most famous being Via Appia. Built in 312 BC, it stretched 560 km from the outskirts of Rome to the Brundisium.
Built on engineering principles, the Via Appia was 10 meters wide and had two main strips paved with gravel laid over a stone foundation. The main area of the road, a kind of priority lane, was separated from the one-way outer lanes by high stone curbs.
The engineering ideas of the Roman road workers are still applied today. Modern roads still use four Roman features: multi-layered paving, curved edges to collect the rainwater, rising above ground level and using parallel ditches to ensure rainwater runoff.
The origin of the modern paving technique is placed in 1775, the year in which Pierre – Marie Tresaguet built the first crushed stone roads, beaten by use, cemented with mud, these were a resistant and durable ground.
Revived by the Scotsman John McAdam, this technique became in the early 19th century what was called “macadam”, a mixture of crushed stone and sand, compacted by stone or cast iron rollers pulled by horses. Another Scotsman, Thomas Telford, facilitated the draining of the infiltrated water by placing the layer of macadam on a bed of large, unattached stones.
Finally, their compaction was perfected, starting with 1860, by using heavy, steam-powered compressors, and after 1925, by using Diesel-powered compressors.
The use of bitumen as a cement for joining paving slabs was already known in Mesopotamia long before Christ. Towards the middle of the 19th century, the study of a new technique began – asphalting. In 1838 the first sidewalk in Paris was asphalted, and in 1854, in the same city, Merian asphalted the first driveway. In 1867, the engineer Charles Tellier had the idea to cover the macadam with a layer of tar and very well compacted sand. In 1892 the first concrete road was built in Ohio (USA).
After the end of the First World War, highways appeared that eliminated intersections and level crossings, with wide roads separating the two directions and bends with a long radius of curvature.
The modern highway is not an American invention, as many might consider, but an Italian one. The paved highways of the twentieth century, a great advantage for motorized traffic, have their origins in the city of Milan, Italian car center, where industrialists created two-lane autostradas to stimulate the population to buy cars.
After all, what’s the point of owning an expensive, fast, and easy-to-handle sports car if there weren’t wide, well-paved, decongested roads to run on?