Funny you should mention that, apapdop, as I've just had the same fun in France, Italy, Turkey, Slovenia, ...
In Turkey, you have OGS, KGS and tickets. OGS is sensor controlled but no obvious barrier, KGS seems to be sensor controlled but does have a barrier and then the usual tickets. Some of the on-ramps are OGS/KGS only so you cannot get a ticket. So, we're on the autoroute with no ticket...after watching the peage section for a while we simply rode through the OGS where we just set the alarms off and carried on! (We rode slowly enough just in case a hidden barrier did come down!)
In Slovenia, they actively direct motorcycles through the OGS equivalent so I didn't pay a penny. What can you do? I was following the directions.
In France I was hit by the CC charge the first time then realised that above all the CC booths is a 2m height restriction and no motorcycles sign and you work out they are directing you through to the autre vehicles (with a long queue and a person). I did end up one time at an unmanned booth in the dark with a soggy ticket which took a few goes to convince to go in the machine.
In Italy I was initially charged the car rate before the person changed his mind!