Pensioners, but >70 can get free local urban travel in some CZ cities, in Praha (DPP) even from 65, BUT you need first to get a kind of customer card, bring foto, pay 60 CzK, valid 5 yrs, as >70 you need to get another one. This is not restricted to EU only. Addon: it seems that from 70 one can now use ID (IF from EU/EER OR passpt-for others. IN Praha/DPP which I visited for in total nearly 14 days spread the last 2 yrs I was never ever checked.
Various Polish cities also offer free travel-mostly from 70, incl Warszawa and Krakow, the major touristy cities, not sure if limited to EU or not.
Slovakia TRAINs also offer free trvael, from 62 or 63 (age slowly rises), for also now only EU as I recall, again a free customer card (bring foto and preferably a printed address to ease communication) must first be had (at customer info pints) =and then for local=osobny=personal trains every trip a free ticket must be got from office. For R-ychlik=fast there are quota and need to REServe-at maybe 1 or 2€ I thought.
Re HU: I remember that when there were only talks about your island in the Northsea going to brexiteer, there were some reports that the odd HU/Volan busdriver told´not valid anymore´ (anyone here has ID, so stand out as a sore threat with a passport book)-well, one cannot expect a simple busdriver to follow all the news at the minute, or?
Actually I am now in FRance and awaiting an overnight train to Provence using an INterRail and here various cities even restrict their lower senior busfares to locals from that town only!