If you stop near a curve or hill crest where other drivers cannot see your vehicle within 500 feet, what should you do with your warning triangles?

49 CFR 392.22(b)(2)(iv) (obstructed-view exception — triangle placed 100 to 500 feet from the vehicle, in the direction of the obstruction); AAMVA CDL Manual Section 2.5.2, p.2-13, Fig 2.10

A hill or curve can hide a stopped vehicle from approaching traffic until it's too late to stop safely, so the standard warning-triangle distances aren't enough in that situation. Moving the rearmost triangle back, to a point 100 to 500 feet out, restores the warning distance drivers need despite the blocked sightline. This adjustment, and its exact distance range, is a specific, testable exception to the standard triangle-placement rules.