ClearGuide Signal Trends: Near Real-Time, Intersection-Level Performance Insights Without Connectivity

Signal Trends, the new set of probe data-based performance metrics within ClearGuide®, helps agencies reduce congestion by monitoring traffic signal performance and identifying deterioration at the intersection without reliance on infrastructure. The module updates intersection data every 10 to 15 minutes, displaying abnormal conditions as they emerge.

The new offering complements Iteris’ detection and traffic analytics software by helping agencies easily identify signal maintenance or traffic congestion problems at more intersections, including where they have not implemented traffic sensors.

Signal Trends leverages anonymized trajectory data from the cloud to provide signal performance visibility across regions or corridors. The tool can search and troubleshoot specific intersections, as well as report corridor trends over time.

With Signal Trends, agencies can better utilize funding with a data-driven, not calendar-based, approach to retiming, eliminating costly data collection by project. The approach allows for the swift discovery of delays to help improve traveler satisfaction, even in situations where field device communication is limited.

Signal Trends offers coverage for all signalized intersections nationwide, with the power of ClearGuide’s precision data processing and traffic analytics.

Signal Trends view of Arrivals on Green at an intersection by movement (left/right/U-turns and through lanes).

ClearGuide Roadways, Signal Trends and SPM form one Total Traffic Solution

ClearGuide Signal Trends integrates seamlessly with ClearGuide Roadways and ClearGuide SPM, collectively generating reports, alerts and recommendations to remotely manage all traffic signals and arterials in one user interface.

Rethinking Retiming: An Orange County Use Case

This California county is using ClearGuide Signal Trends for a full-network approach to signal retiming, eliminating costly data collection by corridor.

The Orange County Transportation Authority funds and manages signal synchronization projects for one of the most populus counties in the U.S. Traditionally, OCTA awarded corridor-specific timing projects to various firms. In 2023, OCTA announced a new, major shift in approach: The OCTA Baseline Signal Synchronization Project, which is to be a network-level synchronization and retiming of all 2,500 traffic signals in the county. Foreseeing that data analytics would play a key role, the county awarded Iteris the project, which leverages ClearGuide as well as Iteris’ signal timing, design, operations and maintenance services.

Signal Trends revolutionizes the data collection process.

• Continuous turning movement count percentages are 24/7 to better establish the relative demand of each movement
• Can be combined with local ground-truth data such as ADTs or approach volumes from SPM
• This accelerates the schedule by eliminating a lot of manual data collection
• Provides a fuller picture of traffic volumes/demand outside of a few manually collected hours and days of turning movement counts

Signal Trends optimizes timing prioritization as well as implementation of the new timing.

• Easily identifies intersection and corridor worst problem areas
• Delivers metrics by movement and visualization of the data through contour reports for fine-tuning
• Provides 24/7 travel times and reliability for before-and-after studies

A valuable complement to ClearGuide Roadways essential travel-time reliability reporting, ClearGuide Signal Trends offers customers the opportunity to learn what is happening at intersections without connectivity.

ClearGuide Roadways:

• Measures travel times and congestion
• Tracks performance trends across a region over time
• Produces real-time alerts to abnormal or notable traffic conditions
• Automatically detects and tracks chronic bottlenecks and traffic queues
• Uses anonymized probe data with no additional hardware or in-field infrastructure

ClearGuide Signal Trends:

• Uses anonymized trajectory data at intersections, displayed in near real-time
• Identifies compromised traffic signal performance, high-delay intersections and problem corridors
• Details specific signals by approach and movementHelps prioritize retiming projects for greatest community impact
• Monitors rapid performance deterioration that can quickly alert users to maintenance issues
• Measures progress through dashboards, route scores and trend reports
• Offers flexible reporting with signal and corridor health visible at regional or local level

For agencies wishing to see even more detailed intersection insights, only Iteris offers both probe SPM and controller-based ATSPM solutions.

ClearGuide SPM:

• Uses high-resolution traffic signal controller data
• Provides detailed metrics for signal retiming and transit preemption statistics
• Diagnoses specific causes of degradation and makes timing recommendations
• Keeps signal timing optimized through further alerts and recommendations
• Produces intersection-level safety reports

Key Signal Trends Reports

Arrivals on Green (AOG) represents the percentage of vehicle arrivals at an intersection that occur when the light is green. Alerts can be customized based on percentage.

Control Delay is the average per vehicle portion of the total travel time through an intersection due to the presence of the traffic signal itself, as opposed to queueing or spillover delays. Alerts can be customized based on the number of seconds in the average control delay.

Split Failures are the number of times vehicles were forced to wait more than one full signal cycle to proceed through the intersection. Alerts can be customized based on the number of split failures.

Signal Trends view of the average portion of travel time through an intersection due to the traffic signal, i.e., Control Delay.

The Upshot You Need Before You Drill Down

As a key component of the ClearGuide platform, Signal Trends identifies when and where there are signal performance issues or areas for improvement, and how they have changed over time. In combination with tools like SPM and Roadways, Signal Trends will then help answer why congestion is occurring, and by measuring the effects of countermeasures, deliver insights into how to course correct.

ClearGuide Signal Trends near real-time visibility at the intersection is available to any agency in the United States as a standalone solution, or as an addition to the existing ClearGuide solutions in use today.

For more information, please request a free demonstration of ClearGuide Signal Trends here.