[Data-Viz] All the “highways” in the world

Subtitle: The name of things we drive on

Not actually all the highways in the world.

We love data visualizations, so we were very excited to find this post on the popular and very safe-for-work (titular reference notwithstanding) r/MapPorn Reddit forum, entitled “All the highways in the world, and nothing else”.

At first glance, the map looks pretty accurate. Particularly interesting is how the United States and Western Europe have constructed so many highways that run along their coasts- if you look closely, the state of Florida is almost perfectly outlined by its own infrastructure.

But at second glance, something is not quite right.  Where is South America, Africa or Australia? It’s certainly true that some of these areas are sparsely populated, or could even be beset by developing infrastructure, but could there really be so few highways?

The answer is in the comments, but more specifically, how the data was curated. Reddit user tabasco-habanero (for whom English is not a native language) had aggregated the data using an amazing free(!) web database called Natural Earth, and according to their comments on the thread, filtered the data to only include “expressways”.

A road is a road is a road, right?

Unfortunately, no.

As you can read in the comments section of the original post, the author gets corrected immediately by someone noting that almost all of Canada and Australia are dark. There are definitely highways there- but the author filtered for “expressway”, which he believed to be inclusive. But then he thought that “highway” was a better translation, so he added that to the graphic. But wait, what are these roads actually called? And why don’t Canada or Australia or South America or Africa have any of them?

These are good questions. Luckily we have Wikipedia.

Five minutes reading the related Wikipedia article on this subject is enough to put you to sleep, if not send you running for cute videos of cats. Here’s an inset on international road nomenclature:

Screen Shot 2015-04-26 at 3.57.54 PM

Expressways have “limited” or “controlled” access- meaning the only way to drive on or off is through ramps and interchanges. There are no stop signs, stoplights or other intersections, and there are no residential egresses or ingresses.

This is an important distinction, as it is fairly common for people to live off of highways, especially in more rural and sparsely populated areas of the world. Speed limits are still generally at expressway levels, between 55 – 75 mph, but it can’t be classified as an “expressway” because someone can drive into a driveway directly from the road on which they’re traveling.

Now let’s go back to the map, which is quite a different map with what we know now. The yellow lines now represent something else altogether: dedicated transportation infrastructure.

The United States, Western Europe, China and Japan have developed systems of highways, interstates, autoroutes, autobahns etc. whose sole purpose is to connect drivers from place to place, from commercial center to commercial center, from port cities to places at elevation, from suburbs to city. They may be impeded by congestion, rush hours or other traffic, but they are implemented and designed to be impeded by nothing else.


Though there are several factors to take into account when determining, why, when and how traffic happens, infrastructure tends to be at the core of the problem.

These expressways are intended to move massive numbers of cars outside of cities and residential areas, ostensibly relieving the pressure from minor roadways. But in developing areas like the Philippines, Indonesia and Colombia, these roads are multipurpose- and not in a good way.

Maybe in a few decades, we’ll see a little more yellow.