Are you permitted in the situation presented, to begin overtaking the vehicle travelling in the right lane?

In the video you are driving in the left lane of a two-lane roadway of a dual carriageway in a city, over a flyover with barriers on both sides; in the right lane ahead of you there is a white car with a trailer under a blue tarpaulin, and further on more cars. You are allowed to start overtaking the vehicles travelling in the right lane. The answer is: yes.

The Road Traffic Act requires you to overtake on the left and prohibits overtaking a power-driven vehicle when approaching the top of a hill, on a bend marked with warning signs and at a junction - except at a roundabout and at a junction where traffic is controlled; a flyover or a bridge is not on this list, and on a one-way roadway overtaking is allowed even on a hill and on a bend. On a dual carriageway the left lane is exactly the overtaking lane: there is no oncoming traffic here, so you do not have to return to the right lane before every oncoming vehicle. Before the manoeuvre you make sure that nobody behind has started to overtake you and that the vehicle in front of you is not signalling a lane change, and you keep a safe lateral clearance; after overtaking, when the right lane is free, you return to it, because the Act requires you to drive as close as possible to the right edge of the roadway.

Legal basis: Art. 24 para. 1-3, para. 7 and para. 8 point 1 and Art. 16 para. 4 of the Road Traffic Act (Prawo o ruchu drogowym)