Are you entering the motorway in the presented situation?

In the video you are driving along a single-lane slip road with barriers on both sides, and on the right you pass a blue sign with a white car symbol - D-7 "expressway" - with sign D-3 above it. You are not entering a motorway - this sign marks an expressway, and a motorway is marked by a different sign, D-9. 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 its end is marked by sign D-8; sign D-9 "motorway", with a symbol of two carriageways and a flyover, marks the beginning or continuation of a motorway. Both types of road are only for motor vehicles, but they differ in speed limits: on a motorway a passenger car may drive at 140 km/h, on a dual-carriageway expressway at 120 km/h, and on a single-carriageway one at 100 km/h. On both, stopping outside designated places and reversing are prohibited, and a vehicle that is stationary because of a breakdown is signalled with a warning triangle placed 100 m behind the vehicle. After joining the expressway, you accelerate to no more than 120 km/h and keep to the right lane.

Legal basis: § 48 para. 1 and 2 and § 44 para. 1 of the Regulation on road signs and signals; Art. 20 para. 3 point 1, Art. 49 para. 3 and Art. 50 para. 2 point 1 of the Road Traffic Act (Prawo o ruchu drogowym)