Google has announced the addition of traffic data for arterial roads to its Google Maps Traffic layer.
Previously, Google provided highway traffic data for select cities. But without arterial traffic data, it was tough to tell which road would make the quickest alternative route. The addition of arterial traffic data eliminates any guesswork.
To check out the new data, just zoom in on a supported city, click ‘Traffic’ in the top right-hand corner of the map, further zoom in to the road level, and watch the roads become green, yellow, red, or red/black depending on the speed of traffic. Green would be a clear route, deteriorating to red/black which signifies stop-and-go traffic.
And just in case you’re wondering how Google manages to pull this real-time traffic service off: read this post. Google explains how it crowdsources the data from cellphones using its Google Maps for Mobile with My Location app. Of course, you can opt-out if this makes you uncomfortable. 
