Mobile millennium: using smartphones to monitor traffic in privacy aware environments


Date Thursday July 9th 2009
Time 4:00-5:00pm
Venue George E. Pake Auditorium, PARC

PARC Forum

This talk describes how the mobile internet is changing the face of traffic monitoring at a rapid pace. In the last five years, cellular phone technology has bypassed several attempts to construct dedicated infrastructure systems to monitor traffic. Today, GPS equipped smartphones are progressively morphing into an ubiquitous traffic monitoring system, with the potential to provide information almost everywhere in the transportation network. Traffic information systems of this type are one of the first instantiations of participatory sensing for large scale cyberphysical infrastructure systems.

However, while mobile device technology is very promising, fundamental challenges remain to be solved to use it to its full extent, in particular in the fields of modeling and data assimilation. The talk will present a new system, called Mobile Millennium, launched recently by UC Berkeley, Nokia and Navteq, in which the driving public in Northern California can freely download software into their GPS equiped smartphones, enabling them to view traffic in real time and become probe vehicles themselves.

The smartphone data is collected in a privacy-by-design environment, using spatially aware sampling. Using data assimilation, the probe data is fused with existing sensor data, to provide real time estimates of traffic. The data assimilation scheme relies on the appropriate use of Ensemble Kalman Filtering on networked hyperbolic first order partial differential equations, and the construction of lower-semicontinuous viability solutions to Moskowitz Hamilton-Jacobi equations.

Results from experimental deployments in California and New York will be presented, as well as preliminary results from a pilot field operational test in California, with already more than 4,000 downloads.



Alexandre Bayen received the Engineering Degree in applied mathematics from the Ecole Polytechnique, France, in July 1998, the M.S. degree in aeronautics and astronautics from Stanford University in June 1999, and the Ph.D. in aeronautics and astronautics from Stanford University in December 2003. He was a Visiting Researcher at NASA Ames Research Center from 2000 to 2003. Between January 2004 and December 2004, he worked as the Research Director of the Autonomous Navigation Laboratory at the Laboratoire de Recherches Balistiques et Aerodynamiques, (Ministere de la Defense, Vernon, France), where he holds the rank of Major. He has been an Assistant Professor in the Department of Civil and Environmental Engineering at UC Berkeley since January 2005. He is the recipient of the Ballhaus Award from Stanford University, 2004. His project Mobile Century received the 2008 Best of ITS Award for ‘Best Innovative Practice’, at the ITS World Congress. He is the recipient of the CAREER award from the National Science Foundation, 2009. Mobile Millennium has been featured already on CBS, NBC, ABC, CNET, NPR, KGO, and the BBC.


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