Observed sidewalk autonomous delivery robot interactions with pedestrians and bicyclists

The recent deployment of sidewalk autonomous delivery robots (SADRs) across university campuses has offered students, staff, and faculty a convenient option for food delivery to their residences or workplaces. However, these low-speed automated food delivery services, which were first commercially deployed on American campuses in early 2019 and continued to offer an important contactless delivery service during the height of the Covid-19 pandemic, traverse campuses on pathways originally designed for pedestrians and bicyclists, creating a potential for conflicts among the different pathway users and potentially unsafe transportation conditions. This study examines one week of field-recorded video from ten locations across the Northern Arizona University campus to help understand the prevalence and severity of SADR-involved interactions with pedestrians and bicyclists. The severity of SADR-involved interactions was quantified by using the surrogate safety measure of post-encroachment time, which was then modeled as a function of conflict- and site-level characteristics to identify predictors of moderate or dangerous conflicts between SADRs and human pathway users. Findings from this study, which provides initial real-world insights into the impacts of SADRs sharing pathways with pedestrians and bicyclists, are intended to help inform facility management strategies capable of supporting the safe introduction of this emerging autonomous freight technology on shared-use facilities in current and potential future settings.