Are you allowed to overtake the articulated vehicle in this situation?

You are approaching a junction where traffic is controlled by traffic lights - the light is green. A lorry with a load is driving in the adjacent lane on your right, and you are driving in the lane to its left (the far left lane is a separate lane for turning left). At a junction with working traffic lights overtaking is allowed, so you may overtake it if you have room and do not obstruct anyone.

The Road Traffic Act prohibits overtaking a power-driven vehicle at a junction, but makes an exception for a roundabout and for a junction where traffic is controlled - and traffic lights are exactly a form of traffic control. If the traffic lights were switched off or flashing amber, the exception would not apply and overtaking at the junction would be prohibited. Before the manoeuvre you check your mirrors and make sure that nobody has started overtaking you.

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