Lanefan
Victoria Rules
Well, at a small-to-medium scale you in fact can force characters down a particular path in how you pre-establish the fiction; simply by how you design/write your adventures.The nature of a railroad is that the dm (or other player) is establishing fiction to force characters down a particular path. You can’t do that if you establish the fiction independent of those characters (other than what they can accomplish with their fictional actions).
For example, they might go into an adventure where you-as-DM have set it up such that if-when they reach area 23 on the map they get teleported into a completely different adventure, in which when they reach the statue of Demogorgon they get plunged into the abyss from which they have only one way out and it's clearly signposted, etc.
Sooner or later, though, you have to give them some downtime; and downtime is when the rails fall away.