here in LA, on the 170 going to the 101, the line will turn from green to amber to blinking red.. I call the latter RED HOT.. those colors let you know the traffic conditions. and they are accurate! when i see amber coming up, right as the red arrow gets close to the amber color, thats where traffic slows. if there are accidents, exit closures, etc, it has an icon to show you.
its accurate in LA and in Atlanta. also the weather updates are pretty cool.