Garmin maps (for the Netherlands)

This topic will list my work to create Garmin maps for end users. To make the process of acquiring and installing the the maps as easy as possible, among others, a webservice will take shape around the maps. Perhaps someday even for other GPS brands as well.

Current maps

  • A normal/generic map using regular Garmin map properties. Product-ID: 50
  • A cycle map where the Garmin map properties are used in a non-standard manner to emphasize cycleways and cycleroutes. Product-ID: 51
  • A Frisian/Fryske language map. This is the normal/generic but uses Frisian names where available. Product-ID: 52
  • A transparent contour map that shows the terrain elevations. This map can be combined with any of the maps above (does not seem to work yet).

Garmin maps: BETA. The maps work but there are a few hickups (see: ‘Problems’ section below).
Website: ALPHA. The website allows to download maps but does not support larger areas (see: ‘Problems’ section below).

Please note: While the developing process for both the maps and the webservice is still early, only maps for The Netherlands will be produced. The Netherlands serves as a testbed and benchmark for almost every OSM service because of its high detail and enormous amount of data available in a small area. When the software and the map generating toolchains are well developed and tested, I will generate maps for the whole world as well. Until then you can download worldwide maps from OSM user Computerteddy.

Map making process
The map making process is essentially very straight forward. Anyone with a bit of computer skills can do it. However, producing the maps for entire countries, continents or even the whole world every week is not something that anyone is able or willing to do, let alone to make a website around it so that non-technical users can benefit from having free OpenStreetMap based Garmin maps.

If you want to create your own set, well, this is how I do it: Currently, every week a new set of maps is produced in a raster of 0.25 by 0.25 degrees based on the latest database dump to allow older Garmin devices to use the maps as well. Osmosis is used to extract the parts that are used for each map from the dump and Mkgmap transforms the bits of OpenStreetMap data into the Garmin image format. Using the --gmapsupp option will generate the combined ‘monolithic’ map and accompanying TDB file as well. I you’re only interested in the monolithic map you’ll probably want to use a less fine grained raster e.g. 2 degrees square.


  • Currently the combined map uses subtiles of 0.25 x 0.25 degrees. The Garmin maps show empty ‘gaps’ on various places of the map between two subtiles. This is because the subtile extraction mechanism (which extracts the relevant data from the OSM planet file) does not include way segments that cross the border of two subtiles. There is no easy workaround for this but several people are working to overcome this major problem. So I expect this problem to be solved soon.
  • Fixed: Unable to install multiple OSM Garmin maps on the same system (e.g. the regular and cycle maps).
  • Fixed: Mapinstaller is not compatible with MapSource version 3.14.1.
  • Fixed: In Mapsource the baselayer is not disabled when zooming in. The result is that the (very rough) baselayer remains visible and distorts the nice details in the map. This is an bug in Mkgmap and will probably be fixed in the coming month or so.

Below is my wishlist in order of importance. If you have more please leave a message.

  • Done: Generate downloads for use in Garmin MapSource by providing an installer. This will make it much easier for non technical folks to use the maps.
  • Busy: Create an application that can download new maps, and update already installed maps, from different web based sources.
  • Add altitude information to the maps. This will enhance the maps usage for outdoor or topographic usage.
  • Expand the website to allow multiple layers (one for every OSM Garmin mapset producer. Yes, I’m not the only one creating Garmin maps).
  • Generate different kind of maps with focus on automotive transport, cycling, etc.
  • Generate routable maps, for many the holy grail of maps. This will involve a lot of work and maybe even require to buy a cGPSMapper license (very expensive!).
  • For the routable maps a paid service might be introduced to compensate for the investment in software. It might also be good for raising some funding for OpenStreetMap itself. This one is food for thought only at the moment…

FYI for Australian users there is a Garmin version of OSM , just for the Australian region

Cool, good to know others are working on this too.

May I ask how large your individual .osm files are that you provide to Mkgmap? Do they cover an entire state in one file? I have some serious rendering problems on the edges of those files and because we have such a high density in data here in The Netherlands I am force to use small areas which results in lots of rendering errors on the tile edges.

you would have to ask the author he post on this forum =>

I’m in the process of changing the web interface such that users draw the area that they’re interested in instead of selecting the tiles that cover that area. This reduces the amount of OpenLayers Features greatly (using a lot of features slowed JavaScript execution to such an extend that it formed a real problem). Maybe other problems emerge from this new approach but eventually it will be user friendlier I think.

The new interface will be based upon the cool stuff that is shown in this OpenLayers example.

I’ve been thinking about an application that can download the selected maptiles and put them on the GPS for you. To make it platform independent and easy to use I first thought of an Java plugin/webstart application, but that takes a lot of time to develop (on top of all the other stuff that needs to be done). So now I’ve come up with an intermediate solution based upon NSIS (Nullsoft Scriptable Installer). The advantages are that I can brew a first version that just installs a predefined map very quickly and then slowly expand the functionality, like keeping a local map cache up-to-date using HTTP downloads and sending maps to a GPS.

Hi Lambertus,

I have tried your NL complete map. So far it works great on my Garmin nüvi 200 but the labels are shown in wrong characters, as: ???.

Whats wrong and can I change something in this map to show the correct characters?


Hmm, I have not encountered such thing yet and I don’t have a Nuvi, so I’ll have to guess here. Can you try and change the language settings to e.g. English?

Could you also publish the map in mac format so I could upload the map using Garmins tools for MacOS X (MapInstall)?

Well, that needs a Windows application called MapConverter. Currently my build toolchain runs completely on Linux, but I guess I could do a post-process on a Windows machine as well.

OK, I changed the language settings to English - but no changes in the character display, still question marks. By the way, the map name in the map-info menu is even displayed with wrong characters.

In the meantime I tried some maps from Computerteddy and there the labels are displayed correctly. Maybe it has something to do with the character coding/code page in the map itself?

Really strange, I don’t use any special settings for language etc, just the defaults. I’ll ask ComputerTeddy if he uses any special settings.

Can you try the ‘NL maptiles for OSX’ version from They’re based on the planet dump from last wednesday. I would like to know if they work…

Wel, I was able to load the maptiles onto my mac using mapmanager, but they crashed both bobcat and the mapinstaller.

The set seemd not to be complete, sort of stopped at about Apeldoorn at the east side of the map, but I can’t see if that was just a mistake from your side or a problem :wink:

HI, well, yes, that is currently about my problem, I don’t have Windows anywhere. It would be nice to be able to build the maps without the use of the Garmin MapConverter.


if there is a new version of the Garmin maps on the website, does that automatically mean that there are new data. previously, I downloaded version 13-3-2007, now I have downloade 28-3-2007, but some changes I made are not visible and download sizes are the same up to the kb.

  1. can I have done something wrong with loading in Mapsource and on my Garmin?
  2. are there changes?

A new version of the Garmin map uses a new version of the planet file from This means that under normal circumstances any data entered in the past week should show up on the new map.

However, it appears there have been some hickups in the planet dump generation in the past two weeks or so. This might have caused the identical filesize and the lack of new features.

Bedankt. Ik zag wel dat bij het uitpakken dezelfde datum van de versie verscheen. Ik heb daar geen aandacht aan besteed (zo iets van vergeten nieuwe naam te geven), maar het kan zijn dat de oude versie onder de installer staat.

sorry for non-Dutch speaking lot amongst you:
Thanks, I saw the same version date when I unzipped the file, but did not pay attention. Could that an old version is still in the installer

Sorry for the late response. You are right, the maps build successfully but used the same old data each time because of a bug in one of the scripts. It’s fixed now.

Hey everybody!

I’m trying to find a good map of Israel for my Garmin Quest, no luck so far…
I found this interesting source of information :

I’m pretty new to the whole GPS thing but from what I see it looks a lot like OpenStreetMap format.
It also sais something about OpenLayer but I can’t really figure out what that is.

The piece of software for mapping that map is RoadMap, if any of you are familliar.

The map format is .rdm.

If any of you have any idea on how to convert those so I can use them with MapSource, please share!!!
Any bit of information will be highly appriciated!!! :wink:

Thanks in advance,