Crowd Sourcing Traffic

Saw Walt Mossberg's video on the new Dash Express navigation system. The system uses uploaded information from other Dash users to provide reports on road and traffic conditions. Other systems, like Garmin's, use traffic data you can subscribe to for an extra fee. A nice example of crowdsourcing. As suggested, this only works if there is a critical mass of other users on the roads you are heading to. Such a network might also have side benefits for truck fleet operators using the same data, decreasing transportation costs. I would guess this is a direction most navigation systems would head towards.