Speaking

Managing safety and efficiency at multimodal intersections is a growing challenge in dense urban environments. This study examines multiple intersections along Washington and Jefferson Streets in Downtown Phoenix, a critical location encompassing the new Downtown Hub light rail transfer stations. This area sees higher-than-average pedestrian traffic and is home to several sports and special event venues, which can increase pedestrian traffic substantially. Using PTV Vissim and Viswalk, we analyzed existing conditions and evaluated treatments designed to reduce conflicts and improve operational performance.

Key strategies included pedestrian scrambles, leading pedestrian intervals (LPIs) and removal of permissive turn movements during red phases, all aimed at reducing vehicle conflicts. The pedestrian simulation utilizing Viswalk’s Social Force Model allowed for the inclusion of natural vehicle-pedestrian interactions and their influence on the performance of other modes in the network. Simulations incorporated future transit routing scenarios and multimodal interactions, ensuring recommendations align with long-term transit operations.

Results indicate improved pedestrian experience while maintaining acceptable traffic performance. The use of PTV Vissim and Viswalk provided a data-driven approach to evaluate complex interactions between vehicles, transit, and pedestrians, enabling the analysis of higher-resolution interactions between modes. This approach provides another essential layer of vehicle-pedestrian interaction to transportation models that helps contextualize traffic analysis results within the broader context of an integrated urban system.

This presentation highlights the fast-tracked conversion of the Boise Avenue & Eckert Road intersection in Boise, Idaho, from a stop-controlled T-intersection to a modern roundabout with upgraded bicycle and pedestrian accommodations. The intersection sits on a steep grade and serves a high-activity corridor leading to one of Boise’s premier parks and the Greenbelt, creating heightened safety risk and user conflicts—especially during peak walking and biking seasons.

Originally initiated as a detailed study, the project shifted abruptly when field investigations revealed severe deterioration of the adjacent Eckert Road bridge, including rotting timber piers requiring posting. The Ada County Highway District (ACHD) closed the bridge and partnered with the Idaho Transportation Department (ITD) to implement emergency repairs, accelerating the roadway and intersection work into an emergency-response design environment.

Attendees will learn practical strategies for delivering a safety-focused intersection redesign under extreme schedule pressure: coordinating across multiple agencies and consultants, advancing a constructible design quickly without defaulting to short-term fixes and integrating complete streets elements in a context with heavy active transportation demand. The presentation will also cover effective public involvement approaches when a highly engaged community has strong expectations for both safety performance and aesthetics.