A team of transportation faculty and graduate students are currently undertaking a study funded by the Florida Department of Transportation (FDOT) to look at the effectiveness of Adaptive Signal Control Technologies (ASCT) in selected corridors in Florida.
What exactly are these technologies? Traditional signal control (termed actuated control) provides a suitable time for each movement by sensing vehicles and extending the green time within a predefined range. These minimum and maximum values are set based on historical data. ASCTs take it a step further and allow for the signal patterns as well as the actual green times and percentage of green for each direction to be adjusted in real time as a function of existing traffic. Traffic adaptive systems or technologies optimize traffic signals based on the current level of traffic conditions. These systems are primarily used to decrease the delays caused by traffic signals and the number of times vehicles have to stop. The goal of this project is to evaluate the traffic operational quality before and after the implementation of ASCT and to identify the best locations and corridors that FDOT can target for funding future ASCTs throughout the state.
Thomas Chase, a doctoral student in the Transportation Program at UFTI working with Dr. Lily Elefteriadou, one of the study’s lead investigators, is managing the overall study including the data collection effort, ensuring tasks are completed on deadline and coordinating with local agencies.
“Adaptive Signal Control is still an emerging technology, so it is great to see agencies incorporate the technology as they are all excited to test the systems,” Chase said. “These systems are designed to improve operations, but FDOT can’t just put them everywhere.”
FDOT has implemented or is in the process of implementing ASCTs in seven locations in the state as a pilot project, and the UF team is evaluating the traffic operational quality before and after the implementation at these locations, as well as maintenance requirements and cost/benefits. The ultimate objective is to provide guidelines for state-wide implementation of ASCTs. The seven corridors to be evaluated are:
- 23rd Street Corridor, Bay County, District 3
- Panama City Beach Parkway, Bay County, District 3
- University Parkway, Sarasota and Manatee Counties, District 1
- US 17/92 Corridor, DeLand, District 5
- Glades Road, District 4
- Newberry Road, District 2
- US 17/Park Ave., District 2
“We are over halfway through the data collection and have seen an improvement in most corridors where we have completed the after study,” Chase said. “We also have to consider the effects of traffic outside of the new signal systems, as traffic will increase and decrease throughout the year.”
Field testing the technology has been both an interesting and challenging experience as not all selected corridors have performed seamlessly. One of the sites in the study experienced increased delays after the system was installed and as a result of this, the maintaining agency identified a need for better detection for optimal performance.
On the bright side of things, in Panama City, at one of the corridors being tested that had experienced a traffic level increase before the study, a local resident told Chase that although she couldn’t immediately identify any decreased delays, she did notice that turning from the side street was much easier since the adaptive system can dynamically re-serve movements before the next cycle.
“Any adaptive signal system will only work as well as the information it receives through detection,” Chase said. “The technologies that are being implemented are not brand new and have plenty of field testing, so we know that they can work safely and efficiently, and we need to focus on finding where they work best. Very high traffic volumes are another area where ASCTs may not make sense, as the traditional plans that an engineer develops would often work as well or better than an Adaptive System.”
Chase hopes that the research team is able to identify the specific characteristics of corridors that operate very well under Adaptive Signal Systems.
“We have a lot of other factors influencing how well the corridor operates, so it is important that we get as specific as possible for guidance to the FDOT,” Chase said. “They should be able to make decisions about where to utilize their limited budget in placing Adaptive Signal Systems on the corridors that need them most.”
The UFTI Advanced Signal Control Technologies research team members are:
Dr. Lily Elefteriadou, Dr. Scott Washburn and Dr. Yafeng Yin (co-principal Investigators)
Dr. Siva Srinivasan (coordinating the safety analysis portion of this study)
The graduate students: Thomas Chase, Yinan Zheng, Pruthvi Manjunatha, Zhuofei Li, Xiaotong Sun, Wei Sun, Ria Kontou, and Liteng Zha. With the assistance of Larry Dorilus, Michael Armstrong, and Shenyang Chen on the data collection process at one or more corridors.
For more information, contact:
Dr. Lily Elefteriadou at elefter@ce.ufl.edu or Thomas Chase at rtchase@ufl.edu.