To keep things moving, the highway and surface street network of Los Angeles has become the most instrumented and managed of any American city. Sensors embedded in the ground and on poles measure rates and volumes, and deliver their data to control centers where it is assembled into a dynamic image of the collective traffic picture. Increasingly automated, signals also flow out from these control rooms, adjusting timings of lights at intersections and freeway metering ramps, dispatching incident response teams, and updating traffic reports, including live maps on the web. These in turn effect the flow, feeding back into the system and changing its form, as indicated by the sensors that send their signals to the control rooms: the loops feeding back to the loops.

Continue to inductive loops.

This online version features 86 of the 194 photographs shown in the original exhibit.