Ex-Google Engineer Reveals How Google Maps Figures Out Destination Times
Most companies who do live traffic compare their predictions against actual time in traffic to tune their algorithms and data sources. The likely result of this is that the companies who have access to the best usage data (ie those who are best able to compare their predictions against reality, which means those who have the most usage) are likely to end up with the best predictions in the medium to long term.Advertisement
In short, there's a ton of data Google is calculating just to tell you that your destination may happen to be 10 minutes away. The company also revealed more on how crowdsourced traffic data helps make Maps even more accurate in 2009.
"When we combine your speed with the speed of other phones on the road, across thousands of phones moving around a city at any given time, we can get a pretty good picture of live traffic conditions," wrote Dave Barth, product manager for Google Maps.Of course, no matter how much data is involved, the time you get will likely never be perfect. As Russell writes, calculating ETAs "is a future-prediction problem, and traffic, while it follows certain patterns, is inherently unpredictable."
Google may know a ton of information, but it doesn't know about the car crash that may have just happened or the school bus making multiple stops in front of you.