Realtime traffic from the likes of Windows Live Search or Google Maps will tell you what traffic is like now. But honestly, what you really want to know is what traffic will be like when you're in that spot. Enter Inrix, which just released a consumer traffic client that puts regular traffic clients to shame.
Got a trip you're going to be making this weekend? Inrix knows whether there'll be a big basketball game or road construction on that route and will be able to guess that you don't really want to go through that particular part of the city on Saturday. Nice. Compatible with WM5 and 6, both Smartphone and PPC (erm, Standard and Pro for WM6), it's 40 bucks at Handango.
Basically, it gathers data from thousands of various sources and then runs Bayesian statistical analysis models to identify traffic patterns. Based on this data, it is possible to actually predict where the congestion will take place, allowing a user -that's us- to circumvent the traffic. It also analyzes
event data (such as sports games, exhibitions, etc.), school schedules, weather forecasts, and more.