How the distance calculation works
The longitude and latitude of a given location (arrival or departure) is determined. The more specific the description of a location, the more accurate the exact location will be. The corresponding country of the location is determined and shown in the app.
This is done to avoid confusion on the exact location. For instance, Amsterdam is not only the capital of The Netherlands but also a small town in the US. Note that in some specific cases the country code is unspecified, often due to geopolitical discussions over land ownership.
Finally, based on the coordinates of the arrival and departure location, the distance between those 2 positions is being calculated. We facilitate 3 different ways of calculating distances:
- Direct (Great Circle Distance): the distance following the shortest path between two points on the surface of a sphere, represented as an arc of a circle whose center coincides with the center of the sphere. In other words, this is the distance between 2 locations that an airplane would take. Note that the GCD can always be calculated between any 2 locations. This is the default distance calculation method.
- By road: the distance following the fastest road connection between both locations. For instance, the distance over highways will be taken for the distance between Berlin and Paris. In case no road connection is available, e.g., between Paris and London, then the platform will indicate "No road connection".
- By rail: the distance following public (people) rail connections between both locations. In case no rail connection is available, e.g., between Paris and New York, then the platform will indicate "No rail connection".
For the above, we use the API services of Here (https://www.here.com/developer/rest-apis).