Changes

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(Figure 2). Additionally, paved roads were developed on the most important highways.<ref>For more on Roman engineered roads, see: Nardo, D. (2015). Roman roads and aqueducts. San Diego, CA: ReferencePoint Press.</ref> 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. Road technology in Europe, in fact, did not improve to any great extent from Roman designs until about the 18th century CE. [[File:Ancient Roman road of Tall Aqibrin.jpeg|thumbnail|Figure 2. Roman road still well preserved today.]]