Wrong, in Austria a Helmet is mandatory for a Threewheeler. Believe me, I already had an encounter with austrian police and at least some of them know valid legislation.
Ha! Having been fined for having the wrong coloured lights over there, I'm not surprised..
But as I asked earlier, is this for Austrian cars and drivers or any nationality?
It's important to separate legislation from regulations applicable to the vehicle and regulations applicable to the driver/occupants. It's harder to argue the latter, but the former should be catered for under EU derogation & agreements/exemptions.
