Two files with OSM data in one map with mkgmap

I got the osm data of germany and the netherlands und want to build one map of this area with mkgmap.
Is this a problem?
My idea is to use the splitter on both osm files and then run mkgmap with all of the resulting smaller osm files.
Or must I build two separate maps and then transfering them with mapsource to my etrex?


In order to be able to compute routes between the two countries, you should run the tile splitter on one file that covers the complete area. The individual country files from Geofabrik (I assume you want to use these) lack the necessary links at the borders.

So what you should do is:

  • Download europe.osm.gz
  • Extract the required part using Osmosis
  • Do the rest (tile splitter, mkgmap)

Yeah but you need a lotta Ram (5-6GB on Wind7) to split europe.osm
Could you circumvent that need using Osmosis?

What is the reason to build your own map? There are plenty of providers of precompiled maps and you can also use my service where you can choose specific tiles to be combined into a single map.

Osmosis can do the splitting for you also but then you won’t have a map that is routable. Splitter is the best option atm.

I tried your service on a smaller area. Yes, it works fine, great service, thank you very much.
But I had a few problems:

The tile I needed was updating for a longer time, so I couldn’t get the map I looked for.

I tried to get a big map, but I got the error too much tiles selected.

I would like to use a map, where the POIs are shown in another priority. When I am zooming in a prebuild map, first I see the phonecells. Thats not interesting for me. First I want to see camp grounds and the fuel stations on the highways. I think to do this I have to change the style file in mkgmap und rebuild the map.

Or do you you have some hints for me?


You must be traveling a lot if you really need so many tiles. :slight_smile: In such cases you can best download entire continents of specific countries from any of the other map providers.

You are able to do that by changing the style file for Mkgmap or add a TYP file that is suitable to your needs to the gmapsupp.img.

I’m working on making the website more flexible so you can have the service do the combining for you but allows you to provide or change map making parameters like TYP files, product id’s etc.

After cutting the osm data with osmosis I can’t use the --route option in mkgmap?

I’m looking for routable maps of europe including an installer for mapsource. There are only lambertus and Team-OID.

Someone told me that I have to edit the style-file of mkgmap for changing the priorities of the POIs and NOT to edit a type-file, because this is only for different colors and the appearance of the symbol.
Isn’t that right?


You could use Osmosis to split a large file into small pieces but then routing won’t work across tile borders. You should use Osmosis to extract the part of the world/continent so that the tile splitter doesn’t need too much memory.

Osmosis does not neatly split roads that cross borders as Splitter does. So you’ll get small gaps in the road network between tiles which kills routability between the tiles ofcourse. Routing within the tiles works normally.

Thinking about this again I don’t think I exactly know how this works, so I’ll better not comment on it :slight_smile:

The style of mkgmap controls at what resolution POIs (and ways) appear as you zoom in and out. The style file also allocates POIs to particular categories (eg. Fuel/Shops etc). You can also do things such as changing the names of POIs in the style file (for example if a bus stop doesn’t have a name you can name make the map contain “Bus stop” rather than “Unnamed transport interchange”).

The TYP file controls the colours and icons that the map is rendered in. You can’t change the resolution at which POIs appear by using a TYP file.

Maps also have a drawing priority which you can set with mkgmap (on the command line not in the style file). If you have two maps in the garmin then the drawing priority controls which map gets drawn on top of the other. The drawing priority may need to be used with the transparent option (another command line option for mkgmap) which makes a map transparent. For example I’m working on a transparent map with a high drawing priority (ie draw on top) which will overlay things that need fixing (eg. no road name) on to the standard UK map I use.

That is interesting. I am rather disappointed, that the OSM POI in the garmin

  • appear as unnamed
  • are grouped wrongly (in my opinion)

So I can not see a useful list for my biking and hiking tours. I would like viewpoints, nature specialties and historical ruins in one folder. And the other leisure stuff in another.

While a cannot convince garmin and neither the OSM community to group (tag) the POI useful (for me), at least I can make my own map, where I can group the OSM POI in my garmin map as I like. Is that so ?

It’s rather difficult to please everyone to their full satisfaction. So many people, so many opinions. Sometimes you feel you will need to do things yourself to get it ‘right’, such is life. Luckily, with OSM, you can do that because both the map data and the software are available.

If you think you have a valuable contribution to make then I think the community would be grateful if you share your better (or alternatively) structured POI groups, style configuration and/or TYP file.

Alternatively you can also try some of the other maps that are available. E.g. the OpenMTB maps, or the open cyclemap. Both provide regional maps only but you might like the styles and use them for your own map.

I know I’m back-quoting an old post, but this sentence isn’t right. mkgmap’s style file allocates a Garmin type ID to an OSM object. It is the Garmin unit itself (or Mapsource) that then controls which category that type ID belongs to. There are very few (if any?) Garmin GPS units where you can edit the category system to better suit your own requirements.


I have a question about how to use the splitter and mkgmap. My problem is, that the switzerland.osm-file is too large to compute as one with mkgmap so I have to use the splitter. After doing that, I have 6 .img-files that need to be put together in one switzerland.img-file.

Which commands I need for that in mkgmap, or is there no way to do it?

Thanks for your help

regards M.

Edit: I normally use the .osm-files from

You’re looking for the --gmapsupp commandline option.

Hi Lambertus

Thanks, that’s exactly what I was looking for!