As you note, the concept of free speech in Europe is somewhat different than in the U.S., but this includes your first sentence not applying in Europe to the same extent. In at least some European countries, the conception of free speech is more of a positive right to speak, subject as you note to limitations (such as an exclusion of racial incitement from the ambit of protected speech). But that may mean that non-governmental entities are also prohibited from interfering with or retaliating for the speech, in at least some circumstances. The most common is that employers are sometimes limited in whether they can fire people for protected speech. Another case is public accommodations, e.g. using political affiliation to refuse service in a hotel or restaurant. I don't know much about transportation law, but it's not inconceivable that there would be some common-carrier rules there.
(The above written with "some" and "may" qualifiers because European laws differ considerably between countries, and sometimes within countries.)