Originally Posted by joveblue
It's useful for comparing distances, giving directions to someone else, quickly adding in a stop along the way, avoiding tollroads, avoiding roads you know are going to be under-construction or over-trafficked, etc.
There's plenty of great uses
I'm not sure when this was added, but if you click on the "Show Options" link under the destination there's a checkbox for "Avoid Tollways." Very useful in Houston.