Google Maps shows real-time information about traffic for most major US cities. To see this, switch to the map or hybrid mode and click on the new traffic button.
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
This tip originally pointed out by Ionut Alex. Chitu