logo separator

Exit hints

25
Jan

There is a new feature to help creating rules in the style file that help with writing style rules that give a bit more help about motorway exits.

The default style is not affected, this is for style authors to use in their styles. It may not work the same on all devices, so you should experiment with the results.

Usually Garmin devices do not display the name of the exit on motorways while routing with mkgmap created maps. The new feature allows you to create a style rule that names part of the exit link road with the junction number, so that when the device tells you to turn onto that road it will include the junction number.

To make this work you have to specify the --process-exits option. This works by splitting each motorway_link into three parts. All parts are tagged with the original tags of the motorway_link. Additionally the middle part is tagged with the following tags:

 mkgmap:exit_hint=true
 mkgmap:exit_hint_ref=ref # tag value of the motorway exit
 mkgmap:exit_hint_name=name # tag value of the motorway exit
 mkgmap:exit_hint_exit_to=exit_to # tag value of the motorway exit

Adding a rule checking that mkgmap:exit_hint=true makes it possible to use Garmin type 0x01 (motorway) for the middle part so that the Garmin device displays the name of this middle part as a hint where to leave the motorway.

An example of such a rule is given below.

highway=motorway_link & mkgmap:exit_hint=true
   { delete display_name;
     name 'Exit ${mkgmap:exit_hint_ref} ${mkgmap:exit_hint_name}' |
          'Exit ${mkgmap:exit_hint_ref} ${mkgmap:exit_hint_exit_to}' |
          'Exit ${mkgmap:exit_hint_exit_to}' |
          'Exit ${mkgmap:exit_hint_name}' |
          'Exit ${mkgmap:exit_hint_ref}' }
    [0x1 road_class=3 road_speed=2 level 1]
Posted by steve on 25 Jan 2013

Latest commits

  • mkgmap-r4767 raise minimum resolution of overview map to 13 to match the alignment of tiles produced by splitter with default resolution ....
    11 jun 2021
  • mkgmap-r4766 map-split.patch - fix possible "Problem writing line ..." message which caused data loss of huge polygons.
    11 jun 2021
  • mkgmap-r4765 rework roundabout checks (roundaboutchecks4.patch by Mike Baggaley).
    10 jun 2021
  • mkgmap-r4763 - fix bug in Coord.distToLineSegment(Coord a, Coord b), it returned Double.NaN when a and b are the same.
    08 jun 2021
  • mkgmap-r4760 minor performance tweak: only create node instance when it is needed.
    06 jun 2021
See more...