ZBB
Emperor
How do ANY of the mapping providers, when they integrate traffic, get their traffic data?
This article from about a year ago has some good info. Navteq gets data from fleet providers (FedEx is mentioned by name). They also use cell phone data -- Navteq is owned by Nokia (and not part of the Microsoft deal...).
The Forgotten Mapmaker: Nokia Has Better Maps Than Apple and Maybe Even Google - Alexis C. Madrigal - The Atlantic