Rail crossings are a different animal. In most, if not all states, all
public grade crossing, whether they are pedestrian, highway, grade separated or at grade, are regulated by the appropriate state agency. In Colorado, that is the
CO PUC. There is an application and approval process with the PUC and the crossing approved. Usually, it is a local government (city, county) or road agency that requests a crossing. In addition, any closures, or improvements also have to be approved by the CO PUC. The railroad has the opportunity for input and there is usually a public comment period. If approved, the railroad will be responsible for any active warning devices, as per FRA regulations, and the associated signs (Cross Bucks). They are also usually responsible, in coordination with the road authority, for the rossing surface planks, dirt, pavement, etc.)
In most cases, if there is a pedestrian crossing added next to an existing road crossing (improvement), it is a change to the road crossing and the adjacent ped crossing becomes a part of and identified with that road crossing and assigned DOT ID Number.
Private crossings are agreements between the land owner and railroad. It is up to the railroad regarding private crossings and use.
Hope this helps.
Mike Ramsey