Via the Google Operating System blog
Google Maps shows real-time information about traffic for many US cities (like Kansas City, New York). To see this, switch to the map or hybrid mode and click on the new traffic tab. Google Maps will add a layer that colors the roads in green, yellow, red, or gray. The colors represent how fast the traffic is moving:
* Green: more than 50 miles per hour
* Yellow: 25 – 50 miles per hour
* Red: less than 25 miles per hour
* Gray: no data available
Until now, this feature was available only in the mobile client of Google Maps.
Update: the official Google Blog mentions that it’s available for 30 major U.S. cities. No word on who’s providing the data.
What it means: this is cool. Google just added the fourth dimension to local search: time. Another “time” application would be to show businesses that are currently open, depending on the day of the week or the time of the day.