Please clarify how OSM maxpeed data is used. The most obvious tag “maxspeed” is probably the easiest case.

How about maxspeed depending on vehicles?
A road that has maxspeed 90 km/h by default and 110 km/h only for cars, the ovbious choice for tagging is


Is this data interpreted in the “right way” (from the point of view of car using a nuvi)?
How about other android navigators (partially offtopic, but maybe some of as are expecting some features that like maxspeed indicator that are only available in the NT format that mkgmap is not yet able to generate)

Hi Muralito,
I’ve moved your post to a new topic. I have no knowledge about maxspeed since I only use it for cycling, so maybe someone else can comment on this?

AFAIK in Lambertus’ maps the speed is fixed depending on road class and surface. The choice of speed limits that Garmin maps give us are very limited, so any translation of OSM maxspeed to Garmin speed steps would have to be heavily rounded.

The NT format is encrypted, so I don’t think we will ever see open source NT maps. For OSM to be really useful for navigation we need to use a native application, like OSMand, etc. Check them out and let us know what you find. :wink:


That depends on the style file you use. Normally, only the plain maxspeed tag is evaluated and gets translated into one of the 8 speed categories available on Garmin devices. Other evaluations are possible: when I create maps for car, I use the strictest value of maxspeed, maxspeed:forward and maxspeed:backward, but if available I use maxspeed:practical…

The maxspeed parameters are set in this file:

My reading of this style is that from the point of view of a car driver, with maxspeed=90 and maxspeed:motorcar=110, road-speed is classified as 5 when it seems 6 would be a better choice.

So, for now the default map with mkgmap works ok, but without using all the data available.
If we want to use all the data ¿two different maps should be made, one for motorcars and another map for truck/bus? Anyway a special map for truck is needed also for using data from other restrictions (hgv=no, maxweight, …)

I have been trying several android applications for a couple of years, but none has the functions i like in my old nuvi 2455, like multiple routes option, advanced detours, and the best hidden feature for OSM mappers, binary log of GPS signal, allowing you to postprocess using DGPS and adjust the data to get improved accuracy, like submeter accuracy with a consumer device.

A mix between OSMand features and GUI would be a good start :slight_smile:
Closed source apps aren’t better, and i don’t like apps with restricted features, and I don’t want apps that sells my data.

Worse, you will need a program into which you put your truck’s size and weight and then it compiles the map for you. And since access restrictions in Garmin maps ony work on walkways, all roads forbidden for your vehicle will be represented as walkways. For travelling on my motorbike I need yet another type of map, where motorways in countries like Thailand, Indonesia, China, … are represented as walkways, because bikes are banned on them.

My prediction for the near future is that Google Maps will kill Garmin & Co. It is preloaded on all Android phones and even reroutes you around traffic jams (although I found out yesterday that this doesn’t work too great; it tried to route me around the address where I was going! :open_mouth: ).


Cannot confirm that. But with a firmware which has the feature “Activity Routing”, many strange effects will occur with the old map format created by mkgmap.
Still, I can show motorways as motorways on my bicycle maps, but I do not use the line code 0x01 as is normal for them, but something like 0x10001 (note: custom type file is also required). Hence my maps look pretty “normal”, but Garmin won’t send me over motorways.