Totally exclude ferries instead of avoiding them

Nobody has claimed this yet.

It seems using `exclude=ferry` parameter, this leads to avoiding them rather than totally excluding them (i.e. I'd like to not have any proposed route in response, instead of preferring the ones without ferries if available).

An example of it is trying to query London to Dublin, or Paris to Guernesey. Mapbox still returns routes, rather than excluding them (although obviously there's no way to avoid ferries on these routes).

Is there a way, either through the API, either through filtering proposed routes, to remove this results ?

Start with the London–Dublin and Paris–Guernsey examples and inspect how the Directions API or proposed-route filtering handles `exclude=ferry`. Determine whether ferry routes can be removed after the response or whether the API must change; done means requests using this option return no route that requires a ferry.

Written by the indexing model from the issue text.