If you live and commute in a congested metropolitan area, odds are you live by the traffic updates on your AM radio. Today, Google bolstered its Google Maps with a traffic gauge that shows you the status of local routes in over 30 cities--including Chicago, Dallas, Los Angeles, New York, San Francisco. speeds directly on the map.
If the traffic reporting is available for your city, you'll see a stoplight pin-cushioned into your map. Click on that to zoom into a view of the traffic conditions. Major arteries turn red, yellow, and green, to reflect how the current traffic is moving. Red translates into a dead standstill or stop-and-go commute; yellow, some delays; green indicates traffic is moving well. You must intuit this yardstick, or read Google's own blog on the subject, since there's no key on-screen. Nonetheless, this approach is very useful for at-a-glance travel planning.
In addition to adding the traffic gauge, Google has also added an estimate of how long your journey will take in traffic. Change your route by dragging Google's suggested route elsewhere on the map, and the driving time estimate changes, too. Nice touch.
Yahoo has already been offering traffic updates on Yahoo Maps. But Yahoo's updates are presented quite differently. And, in some ways, Yahoo is actually more useful; in other ways, not so much. At Yahoo, you get icons and flags pin-cushioned into your map, showing triangles with exclamation points in three colors--yellow for minor, orange for moderate (a good choice for the color blind), and red for severe.
Hover over the icons, and you'll see exactly what is going on at that traffic juntion--for example, is there an accident, a land closure, or something more. Another icon indicates and details whether there's construction along your route. This approach delivers more precise traffic information than does Google's; however, it's not very friendly for an at-a-glance planning strategy. The traffice updates are delivered in real-time, and the map refreshes itself regularly. Unfortunately, Yahoo doesn't supply estimated driving times including current traffic conditions.
Personally, I like the simplicity and estimated driving time provided by Google's approach. But I also want Yahoo's ability to drill down and learn where and what the specific problem spots are. Hopefully, one, or the other of these sites will come up with a way to meld both approaches into one.