Which of the following vehicles can you overtake if you ride a motorcycle on the road, once you go past this sign?

In the photo you are riding on a two-way roadway with a double solid line, and on the right there is sign B-25 "no overtaking". Beyond this sign, when riding a motorcycle, you may overtake only a moped - answer C.

The Regulation on road signs and signals states that sign B-25 prohibits drivers of power-driven vehicles from overtaking multi-track power-driven vehicles. An agricultural tractor is a power-driven vehicle on four wheels - the ban applies. A motorcycle with a sidecar has three wheels in two tracks, so it is a multi-track vehicle - the ban applies, even though it is still a motorcycle. A moped is a two-wheeler, and in addition the Road Traffic Act directly excludes it from the definition of a power-driven vehicle, so B-25 does not prohibit overtaking it. When overtaking a moped, you keep a lateral clearance of at least 1 m and you do not cross the double solid line visible in the photo - a moped is narrow, so it can usually be overtaken within your own half of the roadway. If there were a T-23a plate with a motorcycle under the sign, the ban would apply only to motorcyclists, but its content would be the same.

Legal basis: § 23 para. 1 and 2 of the Regulation on road signs and signals; Art. 2 point 32 and 46 and Art. 24 para. 2 of the Road Traffic Act (Prawo o ruchu drogowym)