Until where do the following road signs remain valid?

1. Until the nearest traffic light, provided that the light is green.
2. Until the nearest bus station.
3. The validity of the sign expires when approaching a densely populated area.
4. Correct answer: Until the nearest junction or until another “speed limit” or “end of speed limit” sign is placed.

WhySpecial speed signs apply until the nearest junction, or until a sign with another speed or an end-of-limit sign. A traffic light does not cancel them.