GraphHopper lets you specify arbitrary (custom) areas using the custom_areas.directory setting in config.yml. During
import all areas that contain a given way will be available for all TagParsers. This way you can adjust
or override the corresponding handleWayTags methods to modify encoded values based on the areas that contain a given
edge.
As a special case of custom areas, GraphHopper automatically includes country borders and finds the country for every
imported OSM way. See the countries.geojson file for GraphHopper's country borders and the next section for some
details about this file. Just as for custom areas the country information will be available to all TagParsers during
import, and of course can also be used to modify encoded values. For example GraphHopper stores the
country information using the CountryParser and the Country encoded value for every edge. Add country to
graph.encoded_values in config.yml to enable this.
Another special case is max_speed for which country-dependent values will be used when
max_speed_calculator.enabled: trueis set,graph.urban_density.threadsis set to at least 1 and- the
countryencoded value is added.
GraphHopper uses so-called country rules to modify the routing behavior depending on country-specific details. There is
a separate implementation of the CountryRule interface for every country (unless it has not been created yet). For
example the AustriaCountryRule changes the default accessibility for highway=track to access=yes, while
the GermanyCountryRule changes it to access=destination. More information about such country-specific rules can be
found in the OSM wiki
for access restrictions
and maximum speeds. Feel free to add
country rules for your country and contribute to GraphHopper!
The countries.geojson file originates from json - see this PR.