The pilot program examined the effects of Adaptive Signal Control Technology (ASCT) on operational cost savings and travel time savings through deployment in the highly congested Bell Road Corridor serving multiple cities of Surprise, Peoria, Glendale, Phoenix, and Scottsdale, AZ. This pilot program was the product of a multi-agency partnership with the cities along the corridor, the Maricopa County Department of Transportation (MCDOT), the Arizona Department of Transportation (ADOT), and the AZTech Regional Partnership, sharing the goal of improving mobility and safety while reducing congestion and travel time seamlessly across jurisdictional boundaries. The partners found that timing plans needed frequent adjustments due to seasonal traffic volume fluctuations, continued growth in the North Phoenix Valley, and recurring demands due to special events. Therefore, the Bell Road Coordination Committee developed a unique approach to test different ASCT systems and strategies. An ASCT system was implemented on this regionally significant, multi-jurisdictional corridor as an alternative solution to constructing costly lanes on an already wide roadway cross-section.
A system engineering process was initiated in 2012 to determine if ASCT was the appropriate solution. The following four project areas with different operating needs and priorities were identified for the Bell Road corridor:
- Project Area 1 was within the limits of the City of Surprise, and had 21 signals, including interchanges with State Route 303 Loop and US 60. The priority of this centralized system is to manage special event traffic.
- Project Area 2 was within the jurisdiction of Cities of Peoria and Glendale, MCDOT and ADOT, and had three signals operated by MCDOT, four Peoria traffic signals, one ADOT signal, and five Glendale signals. This is a distributed system that aims to maintain cross-jurisdictional progression.
- Project Areas 3, within the City of Scottsdale, had a total of 10 signals. The priority for project area 3 is managing traffic during typical weekday peak hours and special events.
- Project Area 4 was within the jurisdiction of the City of Phoenix and ADOT, and had six signals operated by Phoenix and one ADOT signal. The priority for this project area was improving progression of traffic across the I-17 interchange.
Each project area procured the ASCT software through a request for proposal process and procured detection and Anonymous Re-Identification (ARID) travel time readers through a separate low-cost bid procurement. ASCT was initiated for each project area between February 2018 and April 2019.
- The pilot implementation in Project Area 1 led to $9,500 weekday and weekend cost savings each, 20 percent weekday travel time savings and 43 percent weekend travel time savings.
- The pilot implementation in Project Area 2 resulted in $25,900 weekday cost savings, $1,600 weekend cost savings, 51 percent weekday travel time savings, and 7 percent weekend travel time savings.
- The pilot implementation in Project Area 3 facilitated $2,700 weekend cost savings and 31 percent weekend travel time savings, but weekday costs increased by $5,900 and weekday travel time increased by 43%.
- The pilot implementation in Project Area 4 made possible $360 weekend cost savings, 16 percent weekday travel time savings, and 2 percent weekend travel time savings, but costs on weekdays increased by $320.