Title
"Smart" Traffic Signal Technology Update
Description
This report provides an update to the Transportation, Infrastructure, and Planning Subcommittee on the Street Transportation Department's efforts to evaluate and implement "Smart" Traffic Signal Technology within the City of Phoenix street transportation network.
THIS ITEM IS FOR INFORMATION AND DISCUSSION.
Report
Summary
As the fifth largest city in the United States, the City of Phoenix Street Transportation Department (Streets) operates more than 1,160 traffic signals. The technology used by Streets to control traffic is primarily derived from technologies and methodologies from the 1980s and 1990s. That had served the City well as it is based on our grid street system - half mile and mile spacing of most major transportation corridors. As our population has grown and traffic volumes have increased, more signalized intersections have been added to the grid at spacing other than the half mile and mile. This has reduced our ability to move traffic efficiently in multiple directions simultaneously. Providing more advanced technology at signalized intersections to monitor traffic data will help reduce the widespread congestion that is currently occurring at many locations across the City by allowing for active management of the City's traffic signals.
Streets utilizes a Traffic Management Center (TMC) to operate and monitor the City's traffic signals. Since 2018, the objectives of the TMC have been to identify and implement the tools that allow the City to better manage its multimodal transportation network more safely and efficiently through Intelligent Transportation Systems (ITS), also known as "Smart" Traffic Signal Technology. ITS infrastructure includes technologies such as modernized traffic signals, closed-circuit television (CCTV) cameras, vehicular and pedestrian detectors, fiber connectivity, and a centralized traffic management software that allows for real-time traffic management and data collection.
Streets' current standard for all new or rebuilt traffic signals includes new signal controllers (which will accept additional device integration), CCTV cameras to monitor traffic conditions, and non-invasive detection which collects important traffic data. Approximately one-third of our intersections have CCTV coverage, and a little over ten percent of signalized intersections are fully equipped with the latest technology.
Roughly 95 percent of the City's traffic signals are communicating and providing traffic signal data to the TMC. At this scale, manual review of real time traffic data is impractical, leading the TMC to embrace practices and technologies that automate the analysis of traffic signal performance, traffic patterns, and vehicular incidents to reduce congestion, increase safety, and minimize response time. These automated analysis technologies utilize and leverage "big data" concepts.
Traffic Management Center
The Streets' TMC is equipped with TransSuite, an Advanced Traffic Management System (ATMS), which is considered the "brain" of the TMC. This is the centralized software package that plays a critical role in traffic management because of its connectivity to the City's traffic signals and sensors. The ATMS helps traffic engineers manage and operate all traffic signals and sensors to improve traffic operations across the City.
Traffic signal timing coordination and optimization is one of the most cost-effective methods for improving traffic flow, mobility, and safety. The goal is to maximize the flow of traffic along a corridor by coordinating timing at all signals based on the speeds and volumes of a corridor as well as providing sufficient times for pedestrians and bicyclists to cross an intersection in all directions. Proper optimization also helps minimize the number of stops, travel delay, fuel consumption and emissions, and reduces red light running. Using modeling software, the TMC performs corridor analysis and optimization throughout the City daily.
Automated Traffic Signal Performance Measures (ATSPMs) provide big data (thousands of data points per minute) that allows traffic management staff the ability to proactively identify and correct under-performing traffic signals. ATSPMs are defined as a suite of performance measures, data collection, and analysis tools to support performance-based approaches to traffic signal design, operations, and maintenance to improve the safety, mobility, and efficiency of signalized intersections. The performance measures provide substantial real-time data that TMC staff analyzes, including vehicular/pedestrian delay, arterial travel times/speeds, percent arrivals on red/green, vehicular/pedestrian detection functionality, and turning movement counts.
The TMC also utilizes the INRIX Probe Data Analytics (PDA) Suite to support operations, planning, analysis, research, and performance measures generation using probe data mixed with other transportation data. The analytics suite consists of a collection of data visualization tools that allow users to download reports, visualize data on maps, and download raw data for offline analysis. The PDA Suite can provide insight on real-time speed data, the Travel Time Index (TTI), Travel Time Reliability (TTR) metrics, queue lengths, bottleneck ranking, and corridor congestion. Since 2019, Streets staff has actively utilized the PDA Suite for traffic studies, congestion management, and to compare before and after signal coordination and optimization efforts.
Technology Field Pilots
"Smart" traffic signals could have a significant impact on traffic congestion by reducing travel times and greenhouse gas emissions while also better serving pedestrians and bicyclists. To enhance the operations of traffic signal timing and improve corridor progression and coordination, Streets, in partnership with various agencies, evaluates emerging technologies through various field pilots. Due to the high cost to implement these technologies, these field pilots are very critical to determine if the signal technologies are effective and produce the promised and desired results.
Adaptive Signal Control Technology Pilot Deployments
Adaptive Signal Control Technology (ASCT) monitors traffic in real time and automatically adjusts signal timing to reduce congestion and keep traffic flowing. With the enhanced capabilities of adaptive systems, transit, pedestrian, and bicycle movements can be better accommodated, improving mobility for all modes of traffic. ASCT systems also incorporate technologies such as ATSPMs to enhance artificial intelligence (Al) based vehicle detection systems or vehicle to infrastructure (V2I) data exchange.
In 2019, the City of Phoenix partnered with the Arizona Department of Transportation (ADOT); the Maricopa County Department of Transportation (MCDOT); and the cities of Peoria, Glendale, Surprise, and Scottsdale in the "Bell Road Adaptive Signal Control Technology Project." Phoenix and Scottsdale's share of the project deployed KLD's Adaptive Control Decision Support System (ACDSS), while the other partners deployed Rhythm Engineering's lnSync. The City's portion included eight Phoenix traffic signals from 35th to 19th avenues along Bell Road. The overall project included 50 traffic signals on a 16-mile stretch. Through the field pilot it was determined that the KLD adaptive control feature did not provide the desired results, so the system was disconnected by both Phoenix and Scottsdale.
In 2021, the City of Phoenix partnered with MCDOT and the cities of Peoria and Glendale to deploy lnSync in another adaptive signal control project on Dunlap/Olive Avenue and Bell Road. lnSync, an adaptive traffic control system by Rhythm Engineering, uses AI to optimize traffic signals at individual intersections and coordinate signals along arterial corridors to reduce traffic congestion. lnSync overlays on existing traffic signal controllers and adds an lnSync detection system to enable traffic signals to intelligently adapt to real-time traffic demand to improve traffic flow thus improving safety and reducing travel time. This multi-agency pilot project includes implementation on 28 traffic signals along 12 miles of Dunlap/Olive Avenue from 116th Avenue to Interstate 17, which includes five traffic signals within Phoenix. Construction has been completed, and the system is currently in "learning" mode. It is anticipated to be fully operational by December 2022.
Glendale Avenue Pilot with NoTraffic
As part of Maricopa Association of Governments' (MAG) emerging technologies pilots, Phoenix installed the NoTraffic system on Glendale Avenue between Central Avenue and State Route 51 (SR51). The NoTraffic technology is described as a system that can optimize traffic flow in real time and uses an AI-based algorithm that can calculate and improve service by optimizing traffic signals at these intersections.
As part of the NoTraffic system evaluation, quantitative and qualitative analyses were undertaken by the University of Arizona. The operational effectiveness of the NoTraffic system in signal optimization and coordination was evaluated. The initial results showed only minor improvements to traffic flow. However, the TMC saw other benefits such as reliable vehicle detection, accurate turning movement count data, traffic signal performance measures, and an intuitive user interface to analyze data that would support further deployment at locations that would benefit from this specific technology.
Non-Intrusive Pedestrian and Bicyclist Detection Technologies Pilot
Technologies that are currently available or used for vehicle detections and counts are not well suited to collect reliable pedestrian and bicyclist data, which is a priority for Streets. MAG recognized the need to increase the time provided to pedestrians, while also accurately detecting and counting pedestrians and bicyclists. Through MAG's Emerging Technologies Program, a pilot project was created to identify available technologies which claimed to detect and count pedestrians and bicyclists and evaluate their capabilities. Seven different technologies were selected and deployed at five different intersections in the City of Phoenix and the City of Tempe. The evaluation of the pilot is complete, and the final report was published in January 2022. The report showed several of the technologies had promise in delivering stated objectives. Streets staff is considering the deployment of these technologies to provide added safety countermeasures such as extending the time for pedestrians and bicyclists that do not clear the crosswalk, collecting actual walking speed data, identifying conflicts between vehicular and pedestrian movements, and alerts in real time.
Technology Grant Opportunities
Streets continues to evaluate opportunities to pursue federal funding to leverage City dollars to improve our transportation network. The U.S. Department of Transportation released a Notice of Funding Opportunity (NOFO) on Sept. 19, 2022, for Strengthening Mobility and Revolutionizing Transportation (SMART) grants to conduct demonstration projects focused on advanced smart city or community technologies and systems to improve transportation efficiency and safety. A total of $100 million is available for Fiscal Year (FY) 22 grants, and applications are due Nov. 18, 2022.
In addition, the U.S. Department of Transportation also released a NOFO for the Advanced Transportation Technology and Innovation (ATTAIN) Program to deploy, install, and operate advanced transportation technologies to improve safety, mobility, efficiency, system performance, inter-modal connectivity, and infrastructure return on investment. There is a total of $60 million available for FY22 grants, and applications are due Nov. 18, 2022.
Staff is currently reviewing the two NOFOs to identify any potential "Smart" Traffic Signal Technology projects that align with these opportunities.
Department
Responsible Department
This item is submitted by Deputy City Manager Mario Paniagua and the Street Transportation Department.