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VIDBE-Q Volume 63 Issue 4
Fig. 1: Components of the PedPal Safe Intersection Crossing System
The second element of our approach builds on innovative new technology for
real-time adaptive traffic signal control. The Surtrac system combines artificial
intelligence with traffic theory to provide, for the first time, real-time optimization of traffic
flows in complex urban road networks, where (in contrast to suburban corridors) there
are multiple, competing dominant traffic flows that change through the day. Surtrac
takes a decentralized, collaborative online planning approach to signal control. Each
intersection independently senses its locally approaching traffic and generates in real-
time a signal timing plan that moves sensed traffic through the intersection so as to
minimize cumulative wait time. Intersections then share their plans with downstream
neighbors to achieve coordinated behavior at the network level. In the field, Surtrac
shows reductions of 25% in travel times, 30% in number of stops and 40% in wait times.
In the current context, surtrac provides the ability to adjust signal timing plans on a
second by second basis.
