Via LAist we discover that Google’s added traffic data for major city streets in their latest iteration of maps.

“[It] will now show you live traffic conditions on arterial roads in selected cities. Just zoom-in on the city you’re interested in, and click the ‘Traffic’ button in the upper-right corner of the map. As you zoom in closer to an area of interest, we’ll color the arterial roads, in addition to the highways, to show current traffic conditions. Just as with the highways, the colors correspond to the speed of traffic (relative to the speed limit of the road): green is free sailing, yellow is medium congestion, red is heavy congestion, and red/black is stop-and-go traffic.” And yes, it works on the iPhone.