On this road, once you go past this sign, can you park the car at any place on the road, provided that this does not constitute an obstacle to traffic?

Why?

The D-40 residential zone sign on the right marks an area where parking is permitted only in designated places. Not obstructing vehicles or pedestrians does not give you permission to park anywhere you choose. Designated parking spaces are visible in the photograph.

art. 49 ust. 2 pkt 4 Prawa o ruchu drogowym; znak D-40 „strefa zamieszkania”