Coversheet


Agenda Item 5.


TRANSPORTATION AGENCY FOR MONTEREY COUNTY *Memorandum*

To:	Technical Advisory Committee
From:	Doug Bilse, Principal Engineer
Meeting Date:	January 5, 2023
Subject:	Adaptive Signal Operations

RECOMMENDED ACTION:
RECEIVE a presentation on adaptive signal operations.

SUMMARY:

Adaptive signal control technology adjusts the timing of red, yellow and green lights to accommodate changing traffic patterns and ease traffic congestion. Adaptive signal control technologies are best suited for arterials that experience highly variable or unpredictable traffic demand for which multiple signal timing solutions are necessary during a typical time-of-day period. Jason Spenser from WesternSystems will provide a presentation on high-level issues to consider when evaluating the appropriate implementation of adaptive traffic signal operations. This discussion will be limited to adaptive operations issues at a high level without specifying the benefits or limitations of any particular system or product line.

FINANCIAL IMPACT:
This item will not discuss the specific cost of implementing adaptive traffic signal equipment. The presentation should identify aspects to consider when considering procurement of an adaptive system.

DISCUSSION:

Many studies have shown that adaptive signal control improves average performance metrics (travel time, control delay, emissions, and fuel consumption) by 10 percent or more. In systems with extremely outdated signal timing, and experiencing under-saturated conditions, the improvement can be 50 percent or more. Improvement might not be as dramatic in areas where traffic demand is stable/predictable during typical time-of day periods, performance is regularly monitored, and signal timing is well maintained.

In the United States, adaptive signal control technologies are being used on less than one percent of all signalized intersections. The cost of hardware can be an issue, but other barriers include the expertise necessary to configure and maintain the system, and a lack of active performance measurement.

As with any traffic operations strategy, it is essential that a signal operator identify performance outcomes they wish to achieve against their current needs, requirements, and long-range possibilities for their system. The next step is to identify and pursue regional collaboration and integration to successfully deploy and maintain the system throughout its lifecycle. It is important to monitor performance of the deployed system and make periodic adjustments as needed.