The mkgmap default style doesn't understand maxspeed:practical.
Thanks. I was unclear on this. I would suggest that mkgmap should in the default style use the first one of these that is defined: maxspeed:practical maxspeed:advisory (yellow sign, in the US, not a requirement, but advice) maxspeed (legal limit) I am unclear on if advisory is used in non-US places. Here we often e.g. have yellow "45" signs on curves on roads with "55" limit (white) signs, and on exit ramps (slip roads in en_GB, *_link in osm). Sometimes the advisory speeds are sensible, some times they are way too low and occasionally they are too high. A great case for using practical to fix them. I would expect this to be quite necessary in rural UK and IE, as it seems there is a tradition of 100 km/h or 60 mph outside town centers, but at times roads often narrower/twisty such that at least I didn't think it wise. (The US doesn't do this so much; very rarely is the legal limit unsafe. There are dirt roads where :practical should be used, though.)