Are you allowed in this situation to overtake the vehicle?

In the video you are driving in a town in a wide lane of a two-way roadway with a double solid line; in front of you a red car has switched on its right indicator and is slowing down to turn right at the junction next to a stop, and the traffic lights above the junction are switched off. You have the right to overtake this turning vehicle. The answer is: yes.

The Road Traffic Act prohibits overtaking a power-driven vehicle at a junction, except at a roundabout or a junction where traffic is controlled - switched-off traffic lights do not control traffic, so the ban applies here. However, the Act allows overtaking at a junction a vehicle that is signalling the intention to turn, provided that the driver does not enter the part of the roadway meant for traffic in the opposite direction. The red car is signalling a right turn and moving to the right edge, and the lane is wide enough for you to go past it on the left on a motorcycle without crossing the double solid line - the condition of the exception is met. The general rules still apply: you make sure that no one is overtaking you, and you exercise particular caution and keep a safe distance. If the car were not signalling a turn, overtaking at this junction would be prohibited.

Legal basis: Art. 24 para. 7 point 3 and para. 9 and para. 1 and 2 of the Road Traffic Act (Prawo o ruchu drogowym)