The lane guidance feature was open to 100% of users today.
It has been available for L3+ editors in the WME for a while in order to set them up in advance.
During that time we drafted and edited guidelines on how to set them up in Switzerland. Along with the Railroad crossing feature which came out almost at the same time and which is restricted to L4+ editors.
You can read these guidelines by clicking here.
[EDIT - June 2024] Railroad crossings rules have moved to the “Permanent Hazards” rules