Google maps has a new feature that allows you to see traffic. When you are looking at a map, just select the "Traffic" button at the top of the map (show in the image below). Once you select the "Traffic" button, a little widget will pop up (also shown in the image below) and the major roadways will have traffic information added.

Google map showing traffic

By default, the map shows the current traffic conditions. But an even nicer feature is that you can set your travel day and time, and it'll give you the predicted traffic. To change this, select the "change" link in the traffic widget (shown in the image above). Once you do that, the traffic widget will change (as shown in the image below) to allow you set the day and time at which you want the predicted traffic.

The traffic widget expanded to allow you to enter the day and time of travel

This new feature can help you can up with realistic estimates of travel time, even during high traffic times.