Using DRL during the day (i.e. normal visibility) is not mandatory in Austria. You may use them, or dipped beam, if you choose so.
There is one more difference between DRL in EU and NA: in EU, the parking lights must be off, while DRL is on. This is a problem with some older cars, which technically do have DRL, but keep the parking lights on (i.e. pre-F series BMW; the angel eyes are parking light). This is non compliant in EU.
There is one more difference between DRL in EU and NA: in EU, the parking lights must be off, while DRL is on. This is a problem with some older cars, which technically do have DRL, but keep the parking lights on (i.e. pre-F series BMW; the angel eyes are parking light). This is non compliant in EU.