How Did Roads Develop

Roads have been important transport systems for many cultures. While we take their place and presence for granted, as something universal in landscapes today, the reality is several factors often develop before these features become common. Furthermore, roads often reflect levels of authority that begins to reflect how power is distributed in society and where it ultimately is found.

Early Development of Roads

Paths used by travelers likely developed in response to physical or geographic obstacles that made movement slow or difficult if one did not use a given road. However, with the innovation of agriculture spread, roads in the countryside began to be placed in lands between fields. In other words, roads soon were created to control traffic between settlements and to access regions around settlements. Roads became ways in which people could be controlled so that their movements would not disrupt agricultural activity or even private property, as the concept of property itself began to create the idea that roads were common space that helped avoid and access private areas. With agricultural cycles in the Neolithic becoming more common and fixed on the landscape, roads became more fixed features since they proved to be expected ways that one can move without disrupting agricultural activities. Regions that developed pastoral-based economies, on the other had, may have not developed fixed roads, as movement did not need to be regulated or confined to specific spaces.

Roads developed similar in towns and cities. As private areas became established, the roads were utilized as a means to access or avoid private regions in cities all together. At first, roads were not paved, but by the 4th millennium BCE, paving was already developing in the Indus region using baked bricks. Concepts of lane use likely developed as wheeled and human traffic took shape by the 4th millennium BCE if not earlier. Donkeys and onager were likely the most common form of animal in early urban streets to be used as transport. The horse, domesticated in Central Asia, likely did not become prominent on urban streets until the 2nd millennium BCE.

Because roads developed as common space for access that also regulated flow through a city, gateways became important areas that developed to control traffic coming in and out of a city. As cities grew in wealth and importance throughout the 3rd millennium BCE in the Near East and Indus, both these regions likely developed city walls that could only be breached using officials roads via gateways. This helped cities also use these control points as a way to tax trade or regulate what was coming in and out of cities.

Royal Roads

The next major change to roads was the development of the "royal roads" or official government roads that connected very distant towns. This idea developed in the Middle Assyrian and Neo-Assyrian period, from the late 2nd millennium BCE and early 1st millennium BCE. These roads were roads the government had authority over and to utilize them one had to have official permission, unlike normal roads that were considered as common space. The idea of these roads was for developing rapid transport to connect distant places of an empire or large state. Unlike many early roads connecting towns, these long-distance royal roads developed to be more linear or straight, as speed was the primary goal of these roads. Such roads became particularly important as horses developed as the primary transport option for military purposes as well as messengers. Royal roads also helped develop the concept of highways, where a type of road would bypass local roads and help those moving on these roads to more quickly move without going through each city or town along the way. Major nodes or towns, rather than small cities or towns, became the focus in royal roads. Inns and rest places developed as such long-distance roads became important features for large empires. In effect, unlike earlier roads, the growing state needed to create systems of communication that was rapid. Royal roads became the chief vehicle for this along with horses.

Although royal roads proved to be useful for military purposes, as armies after the Assyrian began to adopt such roads, it also led to the development of long-distance trade along secure roadways. In part, long-distance roads helped to spawn the developing Silk Road connecting trade between China and Europe. The long-term legacy of royal roads that allowed armies to move quickly were later adopted by various armies. The modern highway system created in the United States and other countries reflect the concept of rapid movement along large distances by the military, showing that the concepts born in the Iron Age continued to be adopted even by more modern transport. In effect, highways were always seen as initially being for the military above all, but benefits of rapid movement also led to trade thriving along their routes, similar to highways today.

Paved Long-Distance Roads

While highways and royal roads developed by the late 2nd and early 1st millennium BCE, such roads were not paved and often were little more than pathways serviced by rest stations, stables, and inns. Such roads became difficult to travel in wet conditions, making them less than ideal in the wet season. In the Roman Period, road engineering reached a new level. Now, roads were built with deeper foundations and underlain with crushed gravel. This helped to drain roads as water could go through rather than be trapped in the clay. Additionally, paved roads were developed on the most important highways. This included using large capstones. Pavement gave roads additional speed since wheeled carts and chariots could move more quickly in pavement than in dirt roads. Sometimes these roads were construct with multiple layers so that water could be drained and pavement would provide for additional speed. Some of these roads are still used or are visible today.