Is there a layer for displaying mile markers along highways, state and secondary roads?
If no, how do I suggest to OSM to create a layer so we can start adding this data? There are many companies in the transportation industry which need MM to do highway work.
To be most helpful a few data elements would be needed.
Recognition of the various ways roads are written or a drop menu to choose from. SR-56 v. State Road 56 v. S.R.-56 for searching.
Country, state and province filters to improve search results
The normal answer to the questions of the type “how do I suggest to OSM to do X” is “create an example yourself to do X”. There are many more good ideas than people currently doing admin for the main OSM site, so most things get done somewhere else first and if they’re a good idea, get incorporated.