The railroader is the kind of person that will use his personality and blind determination to force his ideas through, regardless of other popular, or learned opinion.
You’ll easily be able to classify a Railroader when you encounter one, they typically talk over other people, usually starting when the have a grasp of an idea and think they can run with it. At this point, they genuinely think they know better than everyone else in the room, including the person who was talking.
You can try to go toe-to-toe with a Railroader, and keep talking over them but unless you have the presence or seniority to carry it off and they stop, it can quickly degenerate into a babble-fest where the rest of the assembled group will be wondering what’s going on.
One strategy is to use distraction to shut them up, like the magicians do. I don’t suggest the, “Look, an eagle!”, approach. More the open handed-stop signal, holding up your finger or pen as a blocker, hand on the shoulder, other ways to knock them off their stride. But be aware when they’ve sussed what you’ve done, they’ll just start off again.
The best strategy is to let them talk themselves out first. Then pitch in with the real solution, as it’s highly probable they have not grasped the whole situation and have gone off half-cocked.
That way you end up looking like the one that knows what they are talking about, which is about right.