In the driver’s community, situations are described where Austrian border guards required negative COVID-19 tests to enter the country. We asked the Austrian Consulate in Poland about it.
In response, we received clear information that the requirement to submit a negative test result, quarantine and registration does not apply, among others, to road transport. Below is a screenshot of the answer (in Polish).
More information can be found here: https://www.gov.pl/web/austria/przyjazd-i-tranzyt-przez-Austrie (in Polish).