In this scenario, before you overtake, must you confirm the car behind isn't already attempting to overtake?

In the video, you are driving in town along a two-way street lined with noise barriers, behind a dark car that is moving more slowly than you. Before you start overtaking, you must make sure that the driver behind you has not started overtaking. The answer is: yes.

The Road Traffic Act states that before overtaking, the driver of a vehicle is obliged to make sure in particular that they have adequate visibility and sufficient space to overtake without obstructing anyone's traffic, that the driver behind them has not started overtaking, and that the driver in front of them in the same lane has not signalled an intention to overtake another vehicle, change direction or change lanes. These three checks are mandatory before every overtaking manoeuvre, even on a quiet street like this one - they are not a recommendation but a condition for the manoeuvre to be legal. Skipping the second one is a common cause of side collisions: you pull out to the left at exactly the moment when someone faster is already overtaking you. The order is simple: the interior mirror, the left exterior mirror, a look over your left shoulder into the blind spot, the indicator - and only then do you change your path.

Legal basis: Art. 24 para. 1 point 2 and point 1 and 3 of the Road Traffic Act (Prawo o ruchu drogowym)