Spatial rules allow you to create rules for certain areas. One example is that the default accessibility for
highway=track in Austria is access=yes, whereas the default accessibility is access=destination in Germany. Other
examples are different max speeds for different countries. More information on different road rules can be found in the
OSM wiki, different accessibilities and
different speeds.
If you have a working GraphHopper setup it is easy to enable Spatial Rules.
We provide a set of approximate country borders, within the GraphHopper repository. If you need exact borders you can
get the exact borders from here. Go to your config.yml file and
uncomment the line: spatial_rules.borders_directory and point it to the directory where your rules are. You need to re-import your graph after that.
Writing your own rules is simple. If you write a rule for a country that is not provided in GraphHopper yet, we'd love if you would contribute your rules. You can have a look at the GermanySpatialRule. Create something similar for your country. After that you have to extend the CountriesSpatialRuleFactory to match your country code.