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Google Maps Now Does Interactive Re-Routing
An anonymous reader writes "Remember how cool it was the first time you used MapQuest or Google Maps or Google Earth? You'll feel like it's the first time again, when you use interactive dragging of routes on Google Maps. Some of the folks from the development team have even whipped up a handy video to explain the concept."
True, but that misses the point. Yes, it was possible before - in the same way that satellite imagery was available on TerraServer for years before Google Maps. The difference between possible and easy is all the difference in the world.
From a strict 'new technology' perspective: Agreed - nothing revolutionary. As an improvement to the way the average Joe can plans trips, done in a incredibly simple, intuitive fashion that non-techies will truly appreciate: Truly awesome.
-NB
The map data has nothing to do with the routes. All Navteq sells to Google and Mapquest is a massive amount of vector-data that maps streets in geo-spatial coordinates. It is up to Google and Mapquest to determine the shortest path between any two points using this data.
It is more difficult than it sounds. Discovering the shortest path in a weighted map is a simple, well known algorithm that any third year computer science major would have studied. The problem is in the weighting. Things such as speed limits, number of traffic lights, road conditions, speed limits of intersecting roads, ourly traffic patterns - all of these affect the amount of time one route takes over another.
Aside from the fact that it is impossible to be up-to-date with this data on a constant basis, some of it changes based on the time of day of your planned trip. For example your morning "shortcut" to work may not be any faster on the weekend when the main route is not as congested.
I think in general, all the mapping sites to a remarkable job given the data they have access to. It is highly unlikely ny one site is "more accurate" than the other picking routes all of the time. What is probably happening is the place where you are going has some factors that have changed recently, or have not been acounted for, in one site vs. the other. You would for certain be able to find counter-examples that make the other site look better at other places in the country.