Driving in Switzerland, on roads where cars are allowed to go, is pretty easy actually as long as you obey the rules to the letter.
Speed reductions take place at the sign - that's not where you take your foot off the accelerator and start to slow down. Speed limits in the tunnels are low and tightly controlled, and there are plenty of tunnels.
Roads are well made, and except for rural roads off the main roads are not especially narrow.
It is true though that on hill and mountain roads (which are often only one narrow lane) where PostBuses go you are required to allow a PostBus the right of way instantly after hearing the special horn - which sounds a motif from the William Tell Overture. The official website of the PostBus plays the sound so you can recognise it. https://www.postauto.ch/en/three-tone-horn
Those roads can be character building. The driver unfortunately has to keep eyes on the road. Everybody gets a much better view through the picture windows of the high-up coach.