Google Maps now has traffic data in several cities. Traffic data is displayed using the now-standard industry color-coding: Green = fast. Yellow = maddening. Red = miserable.
Google joins Yahoo and Microsoft in providing traffic data. Ask.com and Mapquest still don't.
Google still doesn't provide directions for walkers (as Ask.com does), nor for public transit, except for 10 oddly chosen cities (Tampa, Honolulu, and so on, skipping New York, Boston, Los Angeles, San Francisco, and the like.)
None of the sites do what you really need: Create routes that take traffic into account, directing you around jams.
Related: Google Maps adds subway stops, building outlines to cities.
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