Just saw this.
Official Google Blog: You’ve got better things to do than wait in traffic
I had noted only recently when the mapquest navigation app came out that if someone was able to include traffic calculations in their navigation app that they'd have the possibility of gaining some market share from google.
Too late. Google's now got it.
"You don’t have to do anything to be routed around traffic; just start Navigation like you normally would, either from the Navigation app or from within Google Maps. Before today, Navigation would choose whichever route was fastest, without taking current traffic conditions into account. It would also generate additional alternate directions
, such as the shortest route or one that uses highways instead of side roads. Starting today, our routing algorithms will also apply our knowledge of current and historical
traffic to select the fastest route from those alternates. That means that Navigation will automatically guide you along the best route given the current traffic conditions.
Not only can you save time and fuel, you’re making traffic better for everyone else by avoiding traffic jams. Keep in mind that we can’t guarantee that Navigation will be able to find a faster way, but it will always try to get you where you’re going as fast as possible."
I'd like to see a little more details about exactly how it works.
If I'm driving along on the highway with my next turn 20 miles ahead and google maps gets wind of an accident 5 miles down the road, will it all of a sudden tell me to get off the highway and rout me around the accident? If so, how often does it get new traffic data? Or does it only take into account the traffic at the time you create the route?
Based on their blog, I don't think the route changes as you are driving. The blog only refers to route selection at the time of creation.