Thread: How do I decide where to place roads on a world map?

I saw an excellent video in a western civ class years ago that discussed roman road building at length. According to the video, building (paving) the roads was a secondary concern. The primary concern was to keep a standing army from sitting. : ) It was proposed that if soldiers were given too much time of their own, the free time, and the discussions that go with it, could sow discontent and could lead to rebellion. By keeping the troops busy building roads and working at other tasks, in between campaigns, the rulers were actually maintaining their control over their soldiers.

Take that for what it's worth. But I would draw the conclusion that if building roads was primarily busy work (useful in itself but not the primary goal), perhaps there wasn't as much forethought involved in the planning of the roads. If that's true, roads could end up more haphazard than we would otherwise imagine. Following coastlines and rivers, and using the most economical route when dealing with obstacles would certainly always be true but if road-building is a less important project, they may not have assigned their best engineering minds to the project.

I'm not saying, necessarily, that is what happened in medieval Europe. Just offering a different perspective to consider when planning your roads.

Also, not all roads connect cities to cities. Walled cities require a great deal of stone. Wooden structures require lumber. Fields require irrigation systems. Many roads would have to be developed to transport materials. Obviously, most folks would want to build a walled city near a quarry given the chance. But when the prince's new bride says "honey, I'd just love to build our home 'there'", the prince will order the construction to begin regardless as to how far away the quarry may be.

Just food for thought.

This has certainly evolved into a very informative discussion. All of you folks have made brilliant points and opened my eyes to a better understanding of when and where to use roads. I would like to add to the discussion one factor that has not been mentioned tough.

Folks would have followed the easiest routes to landmarks visible at greater distances. They would not have had maps, trails or anything to guide them by except for the occasional glance of that landmark for which to get their bearings again. Once a path was cut, folks could easily and often find shorter or easier ways to get from point to point and over time, those trails would evolve into highways of travel. So, natural landmarks can be a great way to make sense of roadways through rough terrain when towns are no where in the area.

Another form of navigation was using the sun for guidance when traveling among uncharted territory. This could have led folks along miles of impractical and meandering routes that also eventually become established as highways.

This has really been an interesting and thought-provoking thread. I have done a little research on the topic, and thought I would throw in some additional comments.

Originally Posted by savedbygrace

Folks would have followed the easiest routes to landmarks visible at greater distances. They would not have had maps, trails or anything to guide them by except for the occasional glance of that landmark for which to get their bearings again.

Actually, maps have been around for a really long time. Your assumption that "they would not have had maps" really depends on the level of techonological advancement of the civilization in question. For a nomadic, pastoral or tribal culture, one without a written language, it's probably true that they would not have maps of the sort we think of today. However, many of those cultures did have very sophisticated ways of navigating, trail marking, etc.

On the topic of Roman roads...it's true that a large, well funded civilization would be required to actually construct the roads. A culture that had slave labor, or a standing army that needed to be occupied, would almost definitely build such paved roads as the Romans built. These roads were multi-purpose: more efficient transport of armies, yes--but also efficient means of transporting merchandise, raw materials and resources, and important rulers and dignitaries were also very important motivations. Also, one should not assume that because the roads may have been built to keep the armies occupied, the engineering was of lower quality. Roman engineering was EXTREMELY sophisticated, and after the collapse of the Roman Empire, their techniques and knowledge were not surpassed until the 18th-19th centuries. While some Roman roads succumbed to time and the elements, there are thousands of miles of Roman roads still in existence today, and Roman roads were used quite extensively throughout the Medieval period.

Roman roads were known to cut through terrain obstacles, but did not always do so. I'm not sure there is documentary evidence for why theywould do it sometimes and not others (I'd have to do more research on that). There were other societies that also built good roads--there is evidence in Great Britain for sandstone roads paved with clay-gypsum mortar that date back to well before the Roman occupation. Also, the Persian Empire is famous for The Royal Road and other roadway systems, which could allow a courier to travel over 2K km in six days. Additionally, there is evidence that tar was used in road paving in Baghdad in the 8th century (due to the easy availability of naturally occurring petroleum deposits). The main thing all these cultures had in common was that they were large, they had achieved a measure of peace in their realm, and they were reasonably wealthy at the time of road construction.

An area that has been wracked by war, or constant conflicts between tribes, petty kingdoms, etc. would not be capable of building a road system simply because there would be too much disruption, and too much consumption of resources. Constant war would also cause destabilized government, and a constant struggle just to survive, meaning technological and scientific advances (and the inventions accompanying them) would be set aside or abandoned entirely. This would also have an effect on the types of roads available.

Finally, there are many types of unpaved roads, and many ways of paving roads as well. Many forms of minerals have been used in the construction of roads. The Romans made a form of concrete out of lime, volcanic ash, and gravel/sand, that in many ways was superior to modern concrete. Wood planks and logs have been used, bricks have been used (usually in cities, not in highways), etc. Ridgeways, unpaved roads going along the tops of hills, were extremely common in the ancient and medieval periods, and some are still in use today as leisure walking paths. Secondary roads did not just arise from animal paths, but also formed as paths for driving herd animals to market, or as pathways winding between fields.

Hope some of this is useful to someone. One last thing--people often assume that ancient cultures had less technology or were less capable than our modern society. Nothing could be further from the truth. The Romans, the Persians, the Moors, various Chinese Dynasties, the Greeks, the Mesopotamian cultures (Babylonia, Sumeria, etc.)--ALL these civilizations achieved amazing things, and we are still uncovering and rediscovering elements of their technology and scientific knowledge. Even in the Middle Ages, heck even in the so-called DARK Ages, people had access to a lot more sophisticated devices and processes than the average person is aware of. I suggest some of the following if you are interested in this subject:

http://en.wikipedia.org/wiki/Roman_technology
http://www.mnsu.edu/emuseum/prehistory/ancienttech/
http://en.wikipedia.org/wiki/Ancient_Greek_technology
http://en.wikipedia.org/wiki/List_of_Chinese_inventions

Of course, it's usually best to follow up a Wikipedia article (or any encyclopedia, for that matter) with finding the sources listed as references (believe it or not, many Wikipedia articles are well-researched and have extensive references).

Originally Posted by OldGuy

I saw an excellent video in a western civ class years ago that discussed roman road building at length. According to the video, building (paving) the roads was a secondary concern. The primary concern was to keep a standing army from sitting. : ) It was proposed that if soldiers were given too much time of their own, the free time, and the discussions that go with it, could sow discontent and could lead to rebellion. By keeping the troops busy building roads and working at other tasks, in between campaigns, the rulers were actually maintaining their control over their soldiers.

Take that for what it's worth. But I would draw the conclusion that if building roads was primarily busy work (useful in itself but not the primary goal), perhaps there wasn't as much forethought involved in the planning of the roads. If that's true, roads could end up more haphazard than we would otherwise imagine. Following coastlines and rivers, and using the most economical route when dealing with obstacles would certainly always be true but if road-building is a less important project, they may not have assigned their best engineering minds to the project.

If you have the army making the roads, and the central government isn't bothered what the army does as long as the army stays obedient and ready... then the Army gets to decide where the roads go. Most of the major Roman roads (from what I remember) lead out from Rome, to places where the Army expected to need to send Legions in the future. They go from one military objective to another, one defensive point to another, one hotspot of dissent to another. Where more efficient (like say the Alps) they built tunnels using a simple rock shattering technique (build a fire, leave it for a bit, throw water/snow at the heated rocks so they crack and shatter, clear the mess, repeat). They were often short tunnels that cut through the major peaks and tended to be nearly circular (rubble was often used to make the flat road surface rather than hauling it out by hand to dump it in some valley you just take it maybe back 100m and crush it up so you can make it flat).


Roads are the least energy paths, generally, that also meet any major point of interest. You connect all the points of interest to each other by the paths that minimise the distance between the major points and also connects to the minor points along the way. I'm sure there is a nice bit of matrix algebra that could do it... but I can't be stuffed figuring it out or actually doing it.

I tried writing out a reply to this a few times, but in the end I think I'll just write what goes through my mind when I start to build a map.

Roads are going to be one of the last things I do when making a map. My first concern is the geography, because as it was said earlier, animals want to get from point A to point B as quickly as possible. I start by pinpointing the locations where I know I want cities to go for sure. I always plot the ones near obvious water sources first, like near the mouth of a river or on a lake. Rivers are a traditional mode of transportation, so there will often be a lot of cities/towns/villages on rivers, as it makes trade easier.

I then create a new layer for a rough sketch of the roads. No frills here, but I simply connect the cities where waterways cannot reach and it would make sense for there to be roads. If you know some of the history and economics of the world you're creating or at least have an idea, this is where it starts to affect road planning as well as the geography. There are some cities that will become hubs of trade and/or travel, and others will not. Anywhere where trade is a big factor to a city, it will be politically important to the region. There are countless stories in history of battles fought to control these sorts of cities, as they can control how to tax people coming in and out of the city, and therefore receive a cut of the money being earned. (If you want a classic example of a strategically important city, look at Constantinople, nowadays known as Istanbul.)

Also consider religion in the region, and if there are certain sites/cities that are important. Do the people take pilgrimages? Is it something only the extremely devout do or does everyone do it? Is it something only available to the rich or the poor? Look to existing religions for hints on where to go from here. I can't speak for all, but I do know that most of the Christian denominations I've heard of don't say that their believers should take a pilgrimage to Jerusalem in their life, despite the city being extremely important in the history of the religion. In Islam, the Hajj (the pilgrimage to Mecca during a specific time of the year) is one of the five pillars and an important part of showing devotion.

Lastly, as roads are expensive, you might not have all roads, but you might have some trails. These are worn over the passage of time, and make me think of the picture posted earlier in this thread. So, maybe you will have both, depending on your map?

I second what Iapetus said, only I then add in more cities where the roads that connected the main ones end up connecting, crossing rivers, etc.