Hi all, attached is v4 of the patch. The drive-on parameter now accepts the following values: left|right|detect|detect,left|detect,right - detect is equal to detect,right - with detect all roads are counted to find out whether the map is a drive-on-left or drive-on-right map - if the detection doesn't return a clear result, the 2nd option is used - the polish reader only checks the "LeftSideTraffic" string, it doesn't count anything (for now) @Steve, WanMil: I've added methods getDriveOnLeft() to MapperBasedMapDataSource and use it in MapBuilder before a TREFile or NODFile is written to configure the corresponding flags. Classes that are able to detect the dr I think this is a bit cleaner compared to v3 and to trunk.