In this situation, does the vehicle travelling in the left lane pose a hazard?

In the video you are driving in the right-hand lane of a dual carriageway outside town; a red car is overtaking you in the left-hand lane, driving steadily and with a safe gap, and ahead of you a light-coloured car is moving along the shoulder. The vehicle in the left-hand lane is not a hazard. The answer is: no.

The Road Traffic Act requires you to overtake on the left, requires the overtaking driver to exercise particular caution and keep a safe distance, and prohibits the driver being overtaken from increasing speed during the manoeuvre and immediately after it. The red car is doing exactly what it should: it stays in its lane, does not move into yours, does not brake in front of you and does not signal a lane change. Its presence only requires ordinary caution from you - you stay in your lane and do not speed up while it passes you. The principle of limited trust does not tell you to treat every vehicle next to you as an obstacle, only one whose behaviour is out of the ordinary. The real hazard in this scene is on the right: the car driving on the shoulder, which may come back onto the roadway.

Legal basis: Art. 24 para. 2, 3 and 6 and Art. 4 of the Road Traffic Act (Prawo o ruchu drogowym)