Changes

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. <reg> For more on how or why roads first developed, see: Alcock, S. E., Bodel, J. P., & Talbert, R. J. A. (Eds.). (2012). Highways, byways, and road systems in the pre-modern world. Chichester, West Sussex ; New York: Wiley-Blackwell.</ref>

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.<ref>For more on early transport, see: Sherman, D. M. (2002). Tending animals in the global village: a guide to international veterinary medicine. Philadelphia: Lippincott Williams & Wilkins.</ref>

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.<ref>For more on taxing of road transport and movement, see: Nail, T. (2016). Theory of the border. Oxford ; New York: Oxford University Press, pg. 86.</ref>