Again, it depends how we define "railroading" (obviously

). For example, if I design a dungeon for an adventure, and place it just outside the village where the PCs start, it's hardly railroading if I expect the PCs to explore the friggin' dungeon. After all, that's the adventure I designed for them! But there are some players who would resent the fact that I expect them to explore the dungeon. Some players might say, we'll go south instead of north. Who needs a dungeon? And then expect me to make up stuff on the fly.
Incidentally, Knights of the Dinner Table had tons of stories like this. B.A. (the GM) prepares an adventure, but his players decide to ignore the adventure and wreak (sic?) havoc, and resent him for "railroading" them with adventure hooks.