If the trap is encountered alone, in a non combat situation, then yes. Its auto-pass or fail.
But try this.
DM: You charge through the door into the kobold nest. Its a large cavern with high ceilings, about 30 feet across, and about 60 feet deep. It slopes upwards towards an altar, behind which is the kobold chief cleric. Kobolds are... here, here, and here. *places miniatures* They've clearly prepared for you, as evidenced by the spikes here, and here, behind which their archers stand. *points* Roll initiative.
Players: *roll dice*
DM: Ok, the order is, Ranger, Wizard, Paladin, Kobolds, Warlord. Before we begin, here. *DM passes a note to the Ranger, who he knew in advance of the session had a high enough Perception score to notice the traps in the room*
Ranger's Player: OH GEEZ! Guys,
DM: WAIT! You can't show them the note. If you want to tell them something, do it in character on your initiative. And don't refer to specific squares on the board. Use words.
Ranger's Player: Oh, ok. Uh, I'm first, right?
DM: Yeah. Go ahead when you're ready.
Ranger's Player: Ok. Um. I quick draw my bow and send two arrows at the kobolds behind the spiked barricade, one arrow per kobold. I move here, *moves miniature* and yell, "'ware the center staircase!"
Paladin's Player: Heh, so much for charging the altar, I guess. I need a new plan.
Wizard's Player: I've got one... I cast a cloud of noxious, choking fumes targetted here, and here, leaving only the center staircase as a route for the kobolds to escape...