TransDec fuses a rich set of real transportation data obtained from RIITS (Regional Integration of Intelligent Transportation Systems) and NAVTEQ. The RIITS dataset is collected by various organizations based in Los Angeles County including Caltrans D7, Metro, LADOT, and CHP. This dataset includes both inventory and real-time data (with update rate as high as every 1 minute) for freeway and arterial congestion, bus location, events, and CCTV snapshots. Moreover, in order to support diverse ITS applications, TransDec contains the transportation network of the entire US, as well as a wide variety of point-of-interest data provided by NAVTEQ.

 

Source: http://imsc.usc.edu/intelligent-transportation.html