Until which point does prohibitory sign 3.24 'Maximum Speed Limit' (e.g., 50 km/h) remain in effect if not repeated?

1. For exactly 500 meters from the sign.
2. Up to the nearest intersection behind it, or to the end of the settlement if no intersection exists.
3. Until the driver turns on headlights or changes lanes.
4. For the entire administrative region until another highway begins.