Mapper of the Month October 2017: Seppe Santens (Belgium)

translation by escada

Please introduce yourself

I am Seppe Santens, born and raised in Aalter. I work as project lead at the Mobility department of the city of Ghent. My user name, “L’imaginaire”, is the result of a, perhaps not very successful, search for a dj-name, many years ago. I still create some electronic music from time to time, but most of my free time are spend with my two children…


How and when did you discover OpenStreetMap ?

I worked awhile for the Flemish government as liaison between business and IT and during that period I tried to study all “open” projects. My first baby steps in OpenStreetMap five years ago were very modest and perhaps I did not always follow common practice. It took awhile before I started to understand the potential that OpenStreetMap offers and from that moment on I started to map more. I have the feeling that I still need to learn a lot, so it is a pleasure that I was invited to become “mapper of the month”.

What do you map ? Is there an evolution ?

I learn something new about OpenStreetMap every day and discover a lot of new things to map. Sometimes it is related to the road network (e.g. when we were planning to map the new traffic circulation plan in Ghent), sometimes it is about buildings and addresses (thanks to the easy access to GRB-data), but it can also be about a totally different topic. Throughout the years I got more confident to map some more “technical” features.

How do you map ?

I tried out several methods. Mostly from my cosy chair (using JOSM), but I attempt to go out from time to time. It is true that I am still looking for the best method to collect as much information as possible when I am outside, and still being able to do other things. After all I have to make sure that my children cross the street in a safe way. Some of the tools I have used so far are

  •, nice app to add a missing POI in a fast way. I noticed that you have to review them afterwards to make sure all details are mapped correctly.
  • GPS-tracks (recorded e.g with OsmAnd) can be useful, e.g. to map recently constructed roads of paths in forests, something that cannot be done with aerial imagery. However, none of my previous smartphones gave accurate results.
  • I believe in the potential of both Mapillary and OpenStreetCam, but have challenges on their own: I have not managed in attaching it to my bike in a safe way even with the holder which was donated by Mapillary. Further problems I have are avoiding sudden movements, accuracy of the GPS recording, getting the item I want to map into the frame and avoiding to violate people’s privacy. That last one is a labour intensive job if you want to do it properly. I have to admit I should some more time on it myself.
  • Strangely enough, I have not tried the simplest method: printing out a map with all fix-me’s and todo’s on it. I think this method might be the most effective, regardless of all available technology. Something to try out in the near future.

I also try to solve as many warnings as possible in the area’s where I map. Those warnings can come from the JOSM validator or Osmose. Perhaps we should all spend some more time on that ?

Where do you map ?

I mainly map the places I know well or that I have visited, thus this means that Aalter (where I live) and Ghent (where I work) are my most important “target areas”. I would love to enlarge my focus, but there is still a lot to do in both Aalter and Ghent… A mapathon often motivates me to map for HOT, and of course I also map in my travel destinations. Out of boredom, I occasionally use MapRoulette.

Heatmap van Seppe's activiteiten (

What is your biggest achievement as a mapper ?

OpenStreetMap played an important role in the communication on the new traffic circulation plan of Ghent. On the Open Belgium conference I saw for the first time a multi-modal router that compares before and after. Such a tool gives one the possibility to investigate how your route changes due to e.g. prolonged road works or profound changes. The OpenStreetMap-data gave us the possibility to quickly build such a tool with a limited budget. We took a snapshot of the “as-is” situation and used JOSM to model all the planned changes of the “to be” situation. The software of Eurostation (now part of Anyways) did the rest. The site on which the general public could compare both situations attracted more than 125.000 visitors.

The following picture clearly shows the old situation (dashed line) goes straight through the town center, while in the new situation (blue line) the traffic is diverted via the R40, the ringway around the town center :

Circulatieplan Gent

The tool was not only important for the communication with the citizens, but also allowed the planners to better assess the impact of their plans. Last but not least, this was also an important step in the process to update the OpenStreetMap data in a timely manner. The week before the new plan took effect (April 3, 2017), some mappers gathered in a room. The data behind the tool contained some shortcuts, but now it was important to do everything according the OpenStreetMap standards. There were some interesting discussions and a lot of work got done. The end result was that on April 3, everybody with an OpenStreetMap-based navigation tool (such as OsmAnd) could travel effortlessly through Ghent. Even today some of the famous commercial routes cannot do this properly. More information can be found on the website of the city of Ghent.

Why do you map ?

That’s a though one. There are several reasons that I can think of:

  • I keep finding it amazing that so much is possible with crowd-sourced open data. The more I get involved, the more I see the potential. I also try to convince others of this.
  • Mapping is a bit nerdy, even though you do not really need a technical background, so that is a perfect match for me
  • Mapping makes me zen. There is nothing that relaxes me more than trying to map a stream over several kilometers in a detailed way. And when the hours fly by, which could have been used to do a job in the house, there is still the feeling that you did something useful.
  • Mapping has something addictive. Whenever I notice a new road, I have problems to suppress the urge to map it.

What is the most difficult part of mapping ?

The more you learn about OpenStreetMap, the more you realize it is not really easy. Luckily, you can start modestly and learn at your own pace. Mapping or even editing relations was something I stayed away from for a long time. Recently, though, I tried to map one from time to time. Feel free to leave a comment on one of my changesets if you find a mistake. Finding or recognizing incorrect edits requires some craftsmanship that I have not mastered yet. And there is the required willpower to finish something instead of starting yet another topic. Luckily there are no deadlines and perhaps, someone else will finish where you left off.

What are your plans for the near future ?

First of all, I definitely want to completely map the buildings and addresses in Aalter. I try to do this in little chunks to avoid boredom, but also to do it properly. We already have a large number of buildings in Ghent, but this need to be cleaned. So this is most likely the next project. And this is only the beginning, there are several other themes that need some OpenStreetMap-love in the areas that I map.

Are you in contact with other mappers ?

I try to stay in contact with them via the mailing list, Riot and the social media. This also allows me to stay on top of the OpenStreetMap news. I would love to visit more meetups in the neighborhood, but it is not always easy to make time for that.

Do you use OpenStreetMap yourself ?

I notice that over time I use OpenStreetMap more and more to lookup things, while in the past I typically used Google Maps. The tools and apps build on top of OpenStreetMap are very powerful nowadays. I am a rather novice user of OsmAnd, but I use it all the time now, both for long car trips and hiking trips. Both the tool and the data from OpenStreetMap can be used for very different navigation purposes. So now I always carry OsmAnd with me, together with my Leatherman (I’m not a huge fan of the “Swiss knife”).

Are you involved in other OSM projects besides mapping ?

At this moment there is not enough time to pick up new engagements, but maybe thay change in the future.

Is there anything else you want to add ?

I do not feel confident enough to give advice, but I want to share my good intentions. During the past year I noticed that contacts between community members, but also between the community and the administration and the industry are very important for OpenStreetMap. Taking the first step can be daunting, but there are enough experienced mappers that want to help you out. So, my intention is to visit more meetups and have a drink, this will lower the barrier to ask for advice the next time.