Mine does look at traffic and change the route if there is traffic ahead, is that what you mean?
Can't say it's very good at telling you the details. I prefer a friends Volvo, where it tells you it would like to redirect you and offers you the new route and you can assess based on the time saving it suggests and your knowledge of the roads.
I also don't like how my standard Nav would rather direct me down a tiny lane (unsuitable for HGVs kind of thing) than let you sit for 10 minutes in some traffic on a nice A road. I haven't got round to updating though, so perhaps that will help!