Submitted by shop on September 15, 2013
I'm using v4.5 and today I had a route programmed in the car. It was leading me on a route that didn't use the nearby freeway, even though I had a hunch that the longer freeway route would be faster. So I took note of the estimated time to complete the route on the computer's route as I passed by the turn it wanted me to take, as I headed to the freeway. It very quickly recalculated the route, this time using the freeway, and gave me a shorter estimated time of arrival.
So it seems that the route it computes is the shorter distance, but not neccesarily the shorter time.
I hope this is a setting that can be changed in a future software release.