Hello,
Since more than 15 years, the page https://wiki.openstreetmap.org/wiki/FR:Switzerland/Map_Features refers to 741.272 annex A and B (https://www.fedlex.admin.ch/eli/cc/1992/341_341_341/fr) to choose between highway=primary and highway=secondary in Switzerland.
But the only difference between roads listed in 741.272 annex A and annex B is the road number. Roads in annex A have signs with numbers, and not roads in annex B. It is not a very meaningful difference.
In fact, another legal text also defines main roads in Switzerland: 725.116.21 https://www.fedlex.admin.ch/eli/cc/2007/797/fr. There are even online open data maps that show this network: https://opendata.swiss/fr/dataset/hauptstrassennetz and https://map.geo.admin.ch/?layers=ch.astra.hauptstrassennetz&lang=fr&... .
In 2019, we noticed that 741.272 didn't define a satisfactory roads network in Geneva, and alternative mapping rules were written at https://wiki.openstreetmap.org/wiki/Routes_principales_dans_le_canton_de_Gen.... Today, I see that 725.116.21 defines a network that shares several roads with what we have independently mapped as highway=primary in Geneva.
I therefore propose to modify https://wiki.openstreetmap.org/wiki/FR:Switzerland/Map_Features tby adding that roads listed in 725.116.21 should be mapped as highway=primary.
Regards Marc Mongenet