What is the rule under Swiss traffic law (VRV Article 15) when a scheduled public transport bus (Linienbus) indicates its intention to pull out from a bus stop within built-up areas?

1. Following drivers must accelerate and honk to prevent the bus from pulling out
2. The bus must always wait until all traffic has passed for 5 kilometers
3. Following drivers must reduce speed and, if necessary, stop to allow the scheduled bus to leave the bus stop and re-enter traffic flow
4. Bus drivers have no right to indicate