All routes lead to cleaner air

One of the longest running smart transport projects is in Pittsburgh, Pennsylvania, USA. In July 2012, the Robotics Institute at Carnegie Mellon University deployed its adaptive traffic signal technology, Surtrac in nine traffic junction sites in the East Liberty area of the city.

The AI/robotic system treats traffic control at these junctions as a single machine scheduling issue…

Stephen F Smith, research professor and director of the Intelligent Coordination and Logistics Lab, The Robotics Institute, Carnegie Mellon University explained: “At the beginning of each planning cycle, a given intersection perceives the approaching (or already queued) traffic from its local sensors and builds a prediction of when it expects each approaching vehicle to arrive at the intersection. Then, in real-time it constructs a “signal timing plan” (a schedule of ‘green’ times for each intersection phase) that moves all of the sensed traffic through the intersection in a way that minimises cumulative wait time.