OpenStreetMap

Now that I have been mapping on OSM for more than a year, I have started to get a better appreciation for the perspectives and concepts surrounding the OSM project. I do, however, continue to reflect on the Western bias of the whole project. In my humble opinion this is most clearly seen in the classification of roads.

A quick scan of the little icons that are attached to the roads classifications show roads and highways familiar in developed countries. The Motorway is a divided highway (called “limited access” in Canada), the Trunk Road is a major route, and Primary seems to indicate a fairly significant route. Secondary and Tertiary are easily identifiable in the Western world as smaller paved roads.

But things are not so clear in Africa. Many roads are residential in town; they turn into a track as they go out into the countryside; and eventually become walking paths. In short, they defy a simple classification. As I entered the discussion with others in the OSM community, I was encouraged to think of the the classification based on the size of the communities connected by the road, rather than the size or condition of the road itself. Fair enough. Based on this, I attempted to organize a reasonable interpretation of the roads for Rwanda (see: http://wiki.openstreetmap.org/wiki/WikiProject_Rwanda/Motorways)

However, there remain problems (and this, of course, is simply an issue with map making – no drawing will ever adequately portray ‘reality’). I have downloaded the OSM data to my Nuvi, and as I drive I am often confronted by the inconsistencies of simply classifying roads based on the towns they connect. The other day I was on a Tertiary road which showed on the Nuvi as a yellow roadway. There was no indication of the condition of the road, just that it was the shortest route to my destination. In fact, it was such a badly maintained road, I needed to turn back and take a different road. The road quality (or surface) is more important in the African context, but it does not show up in the maps.

Recently, I have noticed some modifications to the road classifications (Track has become Unmaintained Track Road; Unclassified Road has become Minor/Unclassified Road). These two changes will greatly ease the burden of decision making when classifying roads in Rwanda.

In fact, Rwanda is an interesting case study since the roads are being developed at a remarkable pace. City streets are being fixed up; country roads are being fixed up, widened and paved; and plans are in the works for some major highways. Yet, in the countryside, the dirt tracks are still plentiful and for the majority of the population, foot traffic is still the main mode of transportation.

Thank you to OSM for helping us map these features more efficiently. It is exciting to be part of a movement that is mapping the whole world.

Comment from Warin61 on 22 March 2016 at 07:53

A year? Time flys!

Road classification probably done to suit the majority .. western people.

For the less ‘well developed’ using the classification system to indicate what roads to use is the best that can be done. Some map renders will show the road surface (unpaved, dirt, rock, grass, ground are some)add road. There have been attempts to ave road difficulty added but those have been rejected .. probably due to a lack of appreciation of the problem in the ‘less well developed’ places.

‘Tracks’ should be possible to use a vehicle along ..think 4WD? If that is not possible I’d use highway=path… but that is for my part of the world.

Looking at ‘it’… everyone expects things to be a certain way in ‘their’ part of the world .. for example supermarkets have a row of chocolate in some places… in other places loafs of bread are sold frozen. So what is a ‘main highway’ can have a different expectation in different parts of the world.

Comment from Warin61 on 22 March 2016 at 08:00

That did not come out well … an edit.

A year? Time flys!

Road classification probably done to suit the majority .. western people. Simply a function of where OSM started and the support base of people.

For the less ‘well developed’ using the classification system to indicate what roads to use is the best that can be done. Some map renders will show the road surface (unpaved, dirt, rock, grass, ground are some). There have been attempts to have road difficulty added but those have been rejected .. probably due to a lack of appreciation of the problem in the ‘less well developed’ places.

‘Tracks’ should be possible to use a vehicle along ..think 4WD? If that is not possible I’d use highway=path… but that is for my part of the world.

Looking at ‘it’ (people view of their ‘world’)… everyone expects things to be a certain way in ‘their’ part of the world .. for example supermarkets have a row of chocolate in some places… in other places loafs of bread are sold frozen. So what is a ‘main highway’ can be a different expectation in different parts of the world. I think the ‘top’ and ‘bottom’ are about the same in broad terms, but the middle is very different. And the amount of the ‘top’ and ‘bottom’ simply reflects the wealth or poverty of that part of the world.

Comment from Sanderd17 on 22 March 2016 at 11:38

HOT tries to promote this classification: https://wiki.openstreetmap.org/wiki/Highway_Tag_Africa

Comment from escada on 23 March 2016 at 06:22

Just in case you didn’t know yet, OsmAnd can display the road surface.

I don’t know which map style you loaded on your Nuvi, but it should be possible to develop a road-style for it that suits your situation better, e.g. by supporting the surface tags. After all, OpenFietsMap already does this for bicycle roads.

Comment from pnorman on 24 March 2016 at 21:03

highway=track isn’t about road surface and never has been. Unfortunately, some people use it for unpaved roads, which is wrong, and leads to these problems.

Comment from SomeoneElse on 24 March 2016 at 21:12

You’re absolutely right - the highway tags in OSM do have a Western bias (strictly speaking, a Western European bias, since that was where the tags originated - there are parts of the US where they don’t work well, either).

However, as Sanderd17 mentioned above, there’s nothing to stop people from adding more detail - things like surface, tracktype, etc.

It’s also possible, when you’re creating maps for your Nuvi, to process different sorts of data in different ways. For example, when I create maps for mine I have it ignore roads and tracks that are probably private. There are a few questions over at https://help.openstreetmap.org/ that might help with that. Although it’s more complicated than just downloading a map from someone else, it’s not that difficult.

If you get stuck with anything, just ask - there’s a list of ways to get in touch on http://wiki.openstreetmap.org/wiki/Contact_channels that should help.

Comment from redsteakraw on 26 March 2016 at 15:18

What exactly does Western mean anyways? Africa is just as Western geographically than Europe. Wouldn’t it make more sense to describe the bias as being Super-Saharan? The Geographic area is Sub-Saharan (below or south of the Saharan desert), Super-Saharan (meaning above or North of the Saharan desert) are all areas North of the Saharan Desert mainly North Africa and Europe. Culturally speaking does it really make sense to split things Western / Eastern / Non Western? Africa alone is culturally diverse, does it really make sense to lump a whole continent together culturally, the same goes with the “Middle East” and “Asia”? Not to mention immigrants, and other populations that don’t even share the same culture as the population in an area in whole. It also seems to only be deployed to divide people, giving an us them, dichotomy. I feel precision in the language would be better served giving better context and articulation of the differences in this case a geographic area.

As for this problem this is probably best dealt in the editor, having local preferences where the roads can be tagged according to whatever tagging convention there is. In this case it may be better to just tag the road as a road(whatever kind of road) and add the surface tags. That way routing can take into context the conditions, and you still can tag roads differently according to their purpose. If editors had shortcut to these tagged roads or ask for the surface tags more predominantly in the editor. The other thing would simply have armchiar mappers just follow a convention in the instructions and have the validation and proper tags added by the on the ground surveyors / locals.

Comment from BushmanK on 28 March 2016 at 01:07

Highway classification in OSM is not based on road quality, it’s based on road function in the whole network. As it was said above, highway=track is widely used for unpawed roads by mistake, for example. Moreover, in Russia, especially in its Eastern part, certain major roads connecting large cities or even parts of country are unpawed or awfully pawed, and they still are highway=trunk.

Physical and functional properties of roads are separated in OSM, while functional properties are not so easy to determine for large fraction of mappers since there is no clear set of definitions or guideline for it.

So, not classification, but understanding of classification by certain mappers is based on their experience, originating from industrially developed countries.

Comment from Kevin Kofler on 2 April 2016 at 14:14

Many roads are residential in town; they turn into a track as they go out into the countryside; and eventually become walking paths. In short, they defy a simple classification.

In that case, you should split the segment, and tag the relevant parts as highway=residential, highway=track and highway=path. This issue is not specific to Africa, and splitting the segment is the right answer world-wide.

Additionally, some explicit transport mode restrictions can also be helpful especially if using certain vehicles beyond a certain point is explicitly banned or strongly recommended against by signage. The surface= key has already been mentioned by other posters.

Comment from joost schouppe on 4 April 2016 at 07:56

Only just taking into account the size of the connected place is not enough. I believe that when there are two roads connecting two places, and one is the preferred route, that one should have the highest classification. Road classification should help pick routes.

Of course, all extra effort on tagging roads with things like surface and or tracktype are welcome. To me, the western bias in OSM is quite clear in the fact that no main style uses this info to show which main roads are better or worse. The HOT style does an effort, but only at high zoom levels. Check my user diary for an example of what I’d like to see.

Comment from Ivan Garcia on 13 April 2016 at 14:48

Hopefully you can use the tag https://wiki.openstreetmap.org/wiki/Key:tracktype

for tagging the quality of each segment in each road and hopefully more apps and maprenders will make use of that tag later on(like the one in your route calculator).


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