This research was funded by the National Institute for Transportation and Communities, or NITC, a program of TREC at Portland State University. Funding was also provided by the Portland Bureau of Transportation.
Traffic signs and signals -- Oregon -- Portland, Traffic signs and signals -- Arizona, Pedestrians -- Oregon -- Portland -- Safety measures, Signalized intersections -- Oregon -- Portland -- Safety measures, Pedestrians -- Arizona -- Safety measures, Signalized intersections -- Arizona -- Safety measures
As cities and communities nationwide seek to develop Complete Streets that foster livability and accommodate all modes, signal timing control strategies that include pedestrians in the operational decision process are gaining importance. This research tested several efficiency-focused pedestrian treatments – coordination, actuated-coordination, free operation, short cycle lengths – and safety-focused treatment including leading pedestrian intervals and Barnes Dance. Using a software-in-the-loop simulation, the operational impacts of these treatments on all users (vehicles, heavy vehicles, bicyclists and pedestrians) at an intersection were evaluated. Results showed that among the efficiency-based treatments, free operation was most beneficial for reducing minor-street pedestrian delays. Both safety treatments increased major-street vehicle delays. A new pedestrian priority algorithm is proposed and developed, which is designed to prioritize pedestrian service under certain traffic conditions. The algorithm is designed to analyze field data and change the user-defined operational strategy to match the conditions in the field. The developed algorithm was deployed at three separate locations, two of which used a Raspberry Pi device and one used the onboard logic processor of the ASC/3 controller. Before-and-after data analysis showed that the algorithm was successful in reducing pedestrian delay. While this research provides field-implementable solutions for reducing pedestrian delays, there is no one "right solution". Ultimately, choice of a control strategy may rest on operational objectives and geometric characteristics of an intersection. The findings from this research may benefit cities that are looking to create safe, sustainable streets capable of accommodating multiple modes.
Kothuri, Sirisha, Kading, Andrew, Smaglik, Edward, and Sobie, Christopher. Improving Walkability Through Control Strategies at Signalized Intersections. NITC-RR-782. Portland, OR: Transportation Research and Education Center (TREC), 2017. https://doi.org/10.15760/trec.156