Spring 2023 Series

Student Presenter: Amy Wyman, Student in the Oregon State University School of Civil and Construction Engineering. 

Student Advisor: Professor David Hurwitz, Oregon State University School of Civil and Construction Engineering.

Original Air Date: May 10th, 2023

Description

The Manual on Uniform Traffic Control Devices (MUTCD) prohibits positioning a bike lane right-adjacent to a vehicle turn-only lane, citing the configurations’ potential for right-hook crashes. However, the MUTCD does not provide specific guidance for positioning bike lanes that are adjacent to shared bus-only and vehicle turn-only lanes. Further, while right-hook conflicts are relatively well-studied, less research exists on the type and frequency of conflicts which may be found in merging or mixing zones. Researchers at Oregon State University conducted a safety evaluation of different bike lane configurations before and after striping improvements were made at five intersections in Portland, Oregon. The researchers extracted conflict observations from 300 hours of video data collected on the major approaches of the intersections using the American Traffic Conflicts Technique. While conflicts between vehicles and bicyclists on the major approach were of primary interest, observations were also made pertaining to conflicts between bicyclists and vehicles on the minor approach and unique non-conflict interactions. This webinar describes the key findings: in general, striping improvements did not significantly affect bicyclist-vehicle conflict frequency on the intersections’ major approaches. However, the striping improvements were associated with potential conflicts observed between bicyclists and vehicles on the minor approach of the unsignalized intersection. Thus, it is important for practitioners to consider how striping modifications to one approach will affect safety and comfort on all approaches. 

Student Presenter: Parastoo Jabbari, Transportation Research Scientist at Jobi Aviation. 

Student Advisor: Professor Don MacKenzie, University of Washington Department of Civil and Environmental Engineering.

Original Air Date: May 30th, 2023

Description

Emerging technologies in transportation, such as automated vehicles (AVs) and mobility services, are expected to impact travelers’ behavior and choices. However, due to many uncertainties surrounding these new technologies, the magnitude and direction of this impact remain a mystery. In this talk, we discuss modeling individuals’ perceptions of automated vehicle (AV) safety and the importance they place on car ownership affect mode choices involving conventional and automated vehicles in the context of privately owned cars and ridehailing services. To capture these two latent variables, we adopted psychometric questions and designed a stated preference survey based on the participants’ actual travel patterns. Then, we quantified the impact of these latent variables on mode choices using an integrated choice and latent variable model. We will also discuss the impact of improvements in safety perception through scenarios.