In this situation, are you entering the motorway?

In the video you are driving along a slip road between a retaining wall and noise barriers, which joins the roadway of an expressway; on the right there is a blue sign with a white outline of a car - D-7 "expressway" - and below it D-43 "end of built-up area". You are not entering a motorway. The answer is: no.

The Regulation on road signs and signals states that sign D-7 "expressway" marks the beginning or continuation of an expressway, and sign D-9 "motorway" - the beginning or continuation of a motorway. The signs differ in their symbol: on D-7 there is a white outline of a car, on D-9 - two roadways with a flyover above them. Here you see the outline of a car, so you are entering an expressway, not a motorway. On a dual-carriageway expressway a passenger car may drive at up to 120 km/h, on a motorway at up to 140 km/h; on both there is a ban on stopping outside designated places, a ban on U-turns (on an expressway, except at a junction or in a place intended for it) and a ban on vehicles that cannot reach 40 km/h. Sign D-43 below says that at the same time you are leaving a built-up area, so the 50 km/h limit no longer applies - from this point the limit for an expressway applies.

Legal basis: § 48 para. 1 and 2 and § 58 para. 3 of the Regulation on road signs and signals; Art. 20 para. 3 point 1 letter a and b of the Road Traffic Act (Prawo o ruchu drogowym)