Julia Turner at Slate has an interesting article on how the beautifully designed “Man leaving via exit door” pictogram hasn’t caught on with Americans who are used to our big red Exit signs.
This is a great issue where the expectations of the installed base (a.k.a. the entire American population) can make unworkable a potentially more attractive or functional interface that doesn’t meet those expectations. C.f. Dvorak vs. Qwerty.
The article also includes a wonderful example of the Slate offices, sporting two different versions of exit signs (the one on the right apparently was placed as part of a governmental edict). Note the Band-Aid approach of labelling the sign “Exit” in addition to the pictogram (icon), as well as the need to place the sign smack dab in the middle of the door. Even then, it’s likely an inferior design for the vast majority of staffers since everything from its color to its icon violates the cultural expectations of exit signs.
It’s interesting to note that “Way Out” signs (The British equivalent) are also frequently labelled in “caution” colors. Despite the article’s implication, green (“affirmative”) and soothing is often not the color scheme that you should use when you need to direct the user’s attention to something important.