I looked up. Art. 36 para. 4 SVG says: «The driver [...] is not allowed to impede other users of the road [...]», however I don't know what «impede» does exactly mean. Since I often experience that I have to adapt my speed because someone entered the road rather tightly, I think the Swiss are more lax about this. You only «impede» if the other one really has to hit the brake. Maybe.
