Traffic signals have come a long way, evolving from the simple time-based signals of the 1950s to the current dynamic systems that allow for real-time adjustment to traffic conditions. As a result, the data used for intersection control have become increasingly complex and important to transportation agencies, researchers, and private companies involved in developing models and technology. However, a standardized and universal format for the data has not yet been developed.
To remedy this data challenge, U of M researchers compiled intersection control information from traffic signal control professionals throughout Minnesota. This information was used to propose a unified code of Intersection Control Information (ICI) for developing future traffic models and technology systems.
“Historically, the availability of traffic signal control information and data formats has varied across jurisdictions,” says John Hourdos, director of the U of M’s Minnesota Traffic Observatory. “Using Central Traffic Signal Control Systems (CTSCS) can support recent trends toward more dynamic traffic models and controls, as well as advances in automated intelligent vehicles.”
Signal optimization experts at the Minnesota Department of Transportation (MnDOT) are also eager to use CTSCS for managing traffic near construction zones more strategically and effectively in order to combat the frequent and often severe disruption of traffic these zones can cause.
“A unified set of intersection control information is valuable for developing a regional signal timing database to model construction project impacts and provide standardized information for use with connected vehicle technologies,” says Kevin Schwartz, a signal optimization engineer with MnDOT Metro Traffic Engineering.
The MnDOT-sponsored project focused on three main objectives. First, researchers worked to collect intersection control information from all Twin Cities metro-area jurisdictions and automate the importation of this information into each jurisdiction’s CTSCS applications, including MnDOT’s construction design tools.
Next, they identified the most inclusive format to represent all required information. Finally, researchers designed a regional database of unified intersection control information and proposed methods for importing and exporting data between the central database and applications used by local jurisdictions.
A key component of the research project was surveying and conducting in-depth interviews with traffic professionals who work with traffic signal data. “Identifying the needs of different stakeholder groups allowed us to produce an organized, comprehensive format for intersection control information,” Hourdos says.
As a result of this project, MnDOT now has the full range of intersection signal control data used across the state. Researchers determined these data can be imported, stored, and delivered through a cloud-based method.
“With these findings, we can begin to consider projects that use CTSCS to mitigate construction-related traffic delays and support intelligent vehicle technologies,” Schwartz says.