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Key Points re Adaptive Signal Control Tech​

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Adaptive Signal Control Technology is a relatively new, but proven effective, approach to improving traffic flow.  The Federal Highway Administration (FHWA) is actively promoting this but it’s still in only a tiny proportion (under 1%) of intersections nationally.

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In adopting ASCT, Marin would be moving to 21st century solutions to traffic congestion.

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Here are some of the benefits of ASCT:

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FHWA says ASCT provides REAL congestion relief and a significant amount of it.  Per the FHA:

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“On average ASCT improves travel time by more than 10 percent. In areas with particularly outdated signal timing, improvements can be 50 percent or more.”

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ASCT is dynamic.  It adjusts signal timing when there are accidents, construction, and other changes to congestion that fall out of the usual time-of-day pattern.

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Over time, ASCT if cost efficient (and with a much bigger benefit/cost ratio than construction-centric infrastructure projects). ASCT permanently eliminates manual retiming of lights, which is costly, technically challenging, and time consuming.  Hence traditional signals are usually not retimed as frequently as optimal.  Per FHA:

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“Outdated signals also affect State DOT costs. Personnel must respond to citizen complaints when traffic signals do not meet traveler needs. Personnel compile the data for transportation specialists who then analyze the data and develop updated signal timing using the traditional signal timing process before generating their recommendations. Because these specialists must balance the needs of one intersection against system requirements, this is time consuming as well as expensive.”

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ASCT is a GREEN SOLUTION.  ASCT keeps cars from needlessly idling at red lights when the intersection is clear.  That shortens commute times and reduces emissions.

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There are many different types of ASCT systems.  Some require in-pavement sensors and underground fiber-optic cables; others use video detection and/or wireless systems.

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ASCT may be a solution with broad benefit to Marin.  It’s proven.  It works.  And there may be grant money.  The Meadowlands, NJ system cost $13 million and included 120 signals.  They got a Federal Tiger II grant to do this.  The Bay Area’s Metropolitan Transportation Commission has also made grants available for signal system retiming.

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Think what Marin could do if we implemented this more broadly than Drake! Rather than spending $7-12 million to move all the concrete around on a small piece of SFD, there would be much bigger bang for the buck and much more congestion relief if we brought ASCT to the entire SFD corridor (not just Ross to the 101).  Perhaps an initial project would include SFD and all the way through San Anselmo.  Then in future, the Miracle Mile.  It’s good to get out of the district silos and get “whole neighborhood” solutions to problems like traffic that affect a broader area.  SFD congestion ultimately detours to Miracle Mile, Magnolia, and other locales outside of District 4.

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Here are some resources to learn more about ASCT:

 

Adaptive Signal Control Technology: Federal Highway Administration Webpage

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Adaptive Signals Speed Up Even Heavily-Congested Corridors

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Many Studies Show Benefits of Adaptive Signals​​

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Adaptive Traffic Signals, Comparison and Case Studies

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