A couple years ago a 50,000 mile long US bike route system was designed. The system would create a national network of roads/trails for cyclists connecting major cities and creating epic bike touring routes.
Now that the plan is in place As it stands it is up to the states to design the routes and build the signs and other infrastructure for the routes. Of course those things cost money and require staff to work on the projects, things that states don’t really want to devote to cycling projects.
If you want to support the projects contact your local representatives and join the