Do that automatically, and you'll wind up with a lot of broken URLs. Routinely, when fixing broken links on my own site, I punch something in the IA, click on the latest version - and get redirected to the root of some site or other. Not very useful. (The redirect also makes it hard to get back to the URL search results because the IA redirects you so fast that if you simply hit the 'back button', you won't go anywhere.)
