History. A cobblestone Roman road in Pompeii.

A cobblestone Roman road in Pompeii.

The first pathways were the trails made by migrating animals. By about 10,000 BC these rough pathways were used by human hunter nomads following these herds.

Street paving has been found in the first human settlements around 4000 BC in India’s Indus Valley city Harrapa.

The oldest engineered road discovered is the Sweet Track causeway in England, dating from around 3800 BC.

The ancient Egyptians constructed a stone paved road to help move materials for the building of the Great Pyramid in about 3000 BC.

The ancient Chinese constructed an extensive system of roads, some paved, from about 1100 BC onwards. By 20 AD the Chinese road network extended over 40,000 kilometres.

The Incas built fine highways, the Inca road system, for couriers through the Andes, and the Mayans built an extensive network of paved roads in Mexico before the European discovery of the New World.

In ancient times transport by river was far easier and faster than transport by road, especially considering the cost of road construction and the difference in carrying capacity between carts and river barges. A hybrid of road transport and ship transport is the horse-drawn boat in which the horse follows a cleared path along the river bank.

In 500 BC Darius I the Great started an extensive road system for Persia (Iran), including the famous Royal Road which was one of the finest highways of its time. The road was used even after the Roman times. Because of the road’s superior quality, mail couriers could travel 2,699 km in seven days.

From about 300 BC the Roman Empire built straight strong stone Roman roads throughout Europe and North Africa in support of its military campaigns. By the 1st century the Roman Empire was connected by 85,000 kilometers of paved roads.

Road construction and maintenance in Britain was traditionally done on a local parish basis. This resulted in a poor and variable state of roads. To remedy this, the first of the “Turnpike Trusts” was organized in around 1706 to build good roads and collect tolls from passing vehicles. Eventually there were approximately 1,100 Trusts in Britain and some 38,000 km of engineered roads.

Engineered roads in the age of horse-drawn transport aimed for a maximum gradient of 1 in 30 on a macadamized surface, since this was the steepest a horse could exert to pull a load up hill, which it could manage easily on the flat. Notable road engineers from this period are Pierre Marie Jérôme Trésaguet (1716-1796) in France and John Loudon McAdam (1756-1836) in England.

During the industrial revolution the railway developed as a solution to the problem of rutting of the road surface by heavy carts. Instead of trying to build a strong surface across the whole road, the cart was constrained to run either on rails or grooves which could be made of much stronger, wear resistant material.

Today roads are almost exclusively built to enable travel by automobile and other wheeled vehicles. In most countries road transport is the most utilized way to move goods. Also in most developed countries roads are formally divided into lanes to ensure the safe and smooth movement of traffic.