Roads and highways have been principal means by which entire economies and societies have emerged and grown over time. They have contributed positively to the spread of ideas, cultures, languages, inventions, goods, and services. Disease, enslavement, tribute, and warfare have also spread through networks of roads and highways to devastate entire peoples and areas and immeasurably alter the course of history.

Early Roads and Highways

The first roads dating back to the dawn of civilizations
(c. 3000 B.C.E.) were little more than dirt paths worn down by frequent travel from one location to another via wheeled vehicles. Rivers were the main highways of this time period, as goods and people moved up and down their courses and any city that desired to rise to importance was located on a river. Yet within a period of a few hundreds of years, roads became a...