A superb thread has been created over at our forums by Tiny, where he goes into detail about his 32 hour drive across the U.S. As you can see in the map above, the blue line is Google and the red representing Bing. While both services providing the same directions, Bing took two diversions, thus making him choose Google with more trust for the first part of the journey.
At the start Bing calculated a route via Utah, which seems longer than the more direct route of Google. Turns out, even though the number of miles with Google was a smaller amount, the time saved (if any) was minimal due to sped restrictions and construction delays.
Bing didn't stop there with calculated issue prevention. Iowa, instead of Missouri, was chosen by Bing approximately half-way through the journey while Google remained on track with the direct approach. Although a warning was present that some roads may be closed, no alternative route was provided by Google. Following Bing would prove to be less trouble and more smooth.
For the rest of the journey and some final thoughts, head on past the break.