Sorry I couldn’t find an article on this in English, but to summarise: there was a bad crash on this rather dangerous road, and the response from the federal roads office, along with lowing the speed limit slightly and adding barriers, is to ban bikes from riding here.
For some context, this road is on the edge of a lake, with mountains on the other side. There is no reasonable alternative for cyclists. Whereas for drivers using this as a through-route (it is part of a major north-south access), there is a large tunnelled motorway on the other side of the lake that would be a minor detour for most. This is all while another road is being constructed to parallel this one at the cost of CHF 1.2 Billion, to be completed in 2033.
They are nice enough to offer an hourly shuttle for up to 16 cyclists at a time.
I think it’s absurd that cyclists again get the short end of the stick when one driver is unable to control their vehicle (with no cyclists involved). And the speed limit is kept as high as 60km/h when clearly the road should be for local use only where a much lower limit would make sense, and longer distance traffic rerouted to the other side of the lake (which is an extra 10km if you’re heading further south from Zurich for example).
There’s no cycle path between Brunnen and Sisikon, only further south.