Are you prohibited from overtaking a motor vehicle travelling on the carriageway at an intersection?

Yes, overtaking a motor vehicle is prohibited at this junction. The photo shows sign D-1 (priority road) and an approaching junction. Sign D-1 alone does not mean that traffic at the junction is directed. Under art. 24 para. 7 pt. 1 of the Road Traffic Act, overtaking a motor vehicle at a junction is prohibited unless traffic is directed by light signals or by an authorised person. Having priority is not the same as directed traffic.