I read the section to deal specifically with hunting FROM or across the road or right of way (ie shooting at an animal purposely) or discharging a firearm FROM or across the road or right of way. Here it seems less important wether a weapon is loaded or not in transport(open or concealed) but more the action of firing the weapon down, from or across said public road or railway.

“except a landowner or his or her immediate family hunting on land of the landowner, who hunts within 50 yards of a public road, public highway, or railroad, or their rights-of-way, with a centerfire rifle, a shotgun using slug or shot larger in diameter than manufacturer's standard”

This section is more interesting as it appears to allow a legal exception only for property owners and immediate kin where said real property exists within the 50 yard right of way exclusion zone. Meaning I suppose if you lived in a house directly next to the tracks or a highway you could shoot a deer or the like in the yard.