There is a bug in the implementation of the road-speed-min and road-speed-max command. Here is a table of what is happening, and what should happen: Status quo --> Current Behaviour --> Supposed Behaviour - highway with road_speed=X and road_class=Y, next to a point which has the following action added: add mkgmap:road-class ='-1'; add mkgmap:road-class-min='1' ; add mkgmap:road-class-max='3' ; add mkgmap:road-speed ='-1'; add mkgmap:road-speed-min='1' ; add mkgmap:road-speed-max='3' XY ---> XY ---> XY 00 ---> 11 ---> 00 11 ---> 11 ---> 00 22 ---> 11 ---> 11 33 ---> 22 ---> 22 44 ---> 33 ---> 33 45 ---> 33 ---> 33 (34 would also be a logically sound solution, as the decrease was maximum 1, but it decreased 2). While in this case the road-class-max=3 and road-speed-max=3 is working correctly (though of course it is stupid to set a road-class-max if you decrease the road-class or road-speed - so it is debatable on how to logically solve this ), the important bit of road-class-min and road-class-max is heavily failing. Instead of decreasing it, it actually increases it. If you work with add mkgmap:road-class ='+1 ' or mkgmap:road-speed='+1', the same problem is of course happening. -- keep on biking and discovering new trails Felix openmtbmap.org & www.velomap.org