One example could be that you are on a multi lane highway and you have a semi that starts entering your lane, and you are closer to the front of the semi, but still in the trucker's blind spot, you may need to accelerate to get out in front of him rather than fall behind him. Sometimes they can't hear your horn, so honking is worthless. Keep in mind the best way to avoid an accident like this is to never enter this situation. Sorry, this probably isn't the best example. :dunno: