I have fairly recently used OSM maps I made with mkgmap in California and Arizona. The good news is that they basically work, including routing. This is in theory not news, but things seems tricky enough that I thought I'd mention it. In Grand Canyon Village (south rim), I found that at 20m-300m zoom (etrex vista hcx), there were no roads (but there were POIs). At 500m the roads appeared. Plus, I got RoadTrip to have a persistent crash on startup. So I wonder if the levels code is working right, and I have a basic question about what's going on. In the img, I think there are 6 levels, represented by some binary codepoints. There is a table mapping the 6 to actual zoom levels (or the other way around). The style 'options' file has the default list of levels. If this is more or less true, it would be nice to have more error checking, with the use of a level not listed in the levels definition causing an error. Quite likely I am totally off base here, but I wanted to report the odd behavior.