I saw this excellent post "5 Powerful reasons to drive slower..." and immediately felt the need to propound it and hence the link. I'm a firm believer of the points that the author has raised.
Initially when I reduced my speed, the main reason behind it was to lower the fuel consumption for economical and environmental reasons. However, since I've slowed down I've realized one more thing and that is: I can keep my cruise on for longer. Ultimately, this too realizes all the benefits already listed in the post.
Being one of those who've long commutes I've come to realize that accidents are big production stops. They not only affect the ones who cause them but thousands of others who get stranded in the traffic jams caused by these accidents.