Network datasets support the use of Landmarks (Configure directions—ArcGIS Pro | Documentation). When a route is created in Pro, they are included as "events" in the directions instructions (Solved: Re: Spatial Landmarks not recognized in NA - Page 2 - Esri Community). These "events" are not supported in the map viewer but work is in progress (Solved: Re: Spatial Landmarks not recognized in NA - Page 2 - Esri Community).
I have not tested personally but I´m being told this is also the case in ArcGIS Navigator (that Landmarks ("events") are not supported). Is this correct and are there any work underway to include support for Landmarks?
The use case is to include information about restrictions along the route to a driver of a special transport. An example is a bridge where the speed limit is 50 kph but for this type of transport (e.g. very heavy load) the maximum speed is 20 kph. If it is not possible to include this information as a Landmark, is there an alternative workflow?
I can now verify that Landmarks are not supported in Navigator and supporting them is not on the roadmap. However, it is not excluded that they will be supported sometime in the future.