This is the 10960th most frequent Polish word.
europejskimi
"Europejskimi" means "European" in the instrumental plural form in Polish.
In this sentence, the adjective 'europejskimi' is used in the instrumental plural case to describe 'autostradami' (highways), indicating that the highways are related to Europe.
Podróżowałem europejskimi autostradami podczas mojej wycieczki.
I traveled on European highways during my trip.
Here, 'europejskimi' modifies 'standardami' (standards) in the instrumental plural case, showing that the standards are associated with Europe.
Europejskimi standardami kierują się w wielu krajach.
European standards are followed in many countries.
In this example, 'europejskimi' is used in the instrumental plural case to describe 'zwyczajami' (customs), signifying that the customs are characteristic of Europe.