[wongarsu]

Which is still just path finding: estimate travel time for each segment, use travel time instead of distance as edge cost.

Don't take that as a dismissal of Google maps: it's the most impressive path finder I know, working with high performance over long distances, taking into account real time information, and calculating meaningful alternative routes to choose from. It's an impressive piece of technology that actually makes the world a better place by saving humanity a lot of travel time that can now be spent on better activities.

Google Maps would certainly be high on my list of best inventions of the last few decades. At the same time the routing is just a good path finder with a good travel time estimator informed by real time data.

[mannykannot]

Compared to distance, travel time is a more complex and nuanced variable. There are more things that a route planner could do, and I suspect that Google maps (and others) are doing some of them. They include taking into account the variance in the time to transit each route segment (which might be, for example, weather-dependent), preferring simpler routes (including taking account of statistics on missed turns), and taking into account the effect of its -- and others' -- recommendations on the flow of traffic (or even on public safety.)

[Retric]

Gathering data is required to do travel estimates. If Google was using handset data to update congestion information, it would want to send a percentage of users down sub optimal routes to verify they are sub optimal.

[tripzilch]

I would be very upset if they did this, though. I'm not Google's test subject and it would be pretty f%$#@! dehumanizing if they treated me that way.

I'm not a bloody ant or part of their hyper-organism.