This study investigates acceptance of shared autonomous shuttles (SASs) in a suburban area. A model where contextual variables were mediated through trust in SASs and technology optimism was tested. We examined intentions to use SASs without a steward and the significance of social distancing. Data were collected at the start and end of a 2020–2021 pilot involving 922 and 608 participants respectively, operating at SAE level 3. Findings indicate that trust and technological optimism significantly influence the willingness to use SASs, though contextual variables show minimal impact. Older adults and women displayed lower trust and optimism, reducing their usage intentions. These two groups also feel that it is more important to be able to keep social distance while riding SASs. The study suggests that future pilots should avoid negative impacts from using immature technology and address the social needs of specific groups.

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Background Trials with automated mini buses (AV shuttles) are going on in many cities. According to game-theoretic reasoning, in mixed traffic normal road users will soon take advantage of the defensive driving style of the AV shuttles, and may eventually totally block their accessibility (Camara et al., 2018; Michieli & Badia, 2018; Millard-Ball, 2018). So far there are few studies on the interaction between AV shuttles and ordinary road users. The present study is probably the first to look at changes in interaction patterns with AV shuttles in real traffic over time, making it possible to empirically test the predictions based on game theory. Method In order to study ordinary road users’ interaction with AV shuttles, and whether interaction patterns change over time, evidence from two Norwegian pilots at Kongsberg and in Oslo, have been collected. Field surveys and video recordings have been conducted at both places and repeated over several months to measure any changes in behaviour. Results Results from survey analyses show very small changes in pedestrians’ interactions with the AV shuttles over time, whereas cyclists seem increasingly to take advantage of the defensive driving style of the AV shuttles. Video data will be analyzed during spring 2020 and results will be presented at the conference. Possible mechanisms producing the differences between cyclists’ and pedestrians’ interactions with the AV shuttles, will also be presented and discussed at the conference. Conclusions Survey results show that pedestrian interaction with AV shuttles do not confirm with the hypothesis based on game theoretic modelling. However, cyclist interaction seems to change over time in line with the game theoretic expectations.@en

The current paper presents the results of behavioural observations in a field experiment with automated shuttles in Oslo, Norway. Video observations were conducted at five fixed locations along a challenging 1.2 km automated shuttle line with varying traffic conditions. Observed interactions between vulnerable road users and automated shuttles were coded using a predefined codebook, which allowed a structured quantitative analysis. The paper identified several potentially risky types of situations in which the automated shuttles did not always behave according to the traffic rules. Generally, the automated shuttles failed to give way to pedestrians at pedestrian crossings in 26%–50% of the interactions. Right-turning shuttles failed to yield to cyclists going straight in 38% of the interactions at observation Site 1 (the only location where the automated shuttle takes a right turn). In majority of same direction interactions between cyclists and automated shuttles, the interactions resulted in the cyclist overtaking the automated shuttle, usually on the left-hand side. Generally, the paper found little evidence of road users trying to bully or otherwise take advantage of the defensive driving style of the automated shuttles and identified only a limited number of interactions in which a vulnerable road user behaved ignorant or aggressive towards the automated shuttles. In addition, the paper found very little indication of temporal effects that suggest changes in the interaction patterns over time.@en

Background Autonomous shuttles (AS) could grow to be more efficient, greener, safer and cost-efficient than current transport solutions. To harvest the full potential of future transport, we depend on their public adoption. The employment of shared, stewardless electric AS will create a novel social situation which there is a paucity of knowledge about. The main public transport provider in the Oslo-region, Ruter, seek to develop a mobility-as-a-service using small stewardless robot taxis for 6-8 passengers. Their shuttles are modified vans that might feel intimate. This novel social situation of being picked up at home by a stewardless AS, may impact the adoption of such services. Previous research has explored theoretical frameworks such as the Unified theory of acceptance and use of technology (UTAUT), which recently was molded into the Multi-Level Model on Automated Vehicle Acceptance (MAVA). No research has yet investigated the role of the social situation for AS acceptance or tested the MAVA experimentally. The current study will explore how the social situation affects acceptance of AS using an experimental design. Experimental conditions are based on key constructs identified in the MAVA and the theory of Social Dominance Orientation (SDO). Possible moderating effects of personality traits are also studied. Method This study will build on previous research from pilots near Oslo that show ambivalent reactions to sharing AS with strangers. We will gather data using a large-scale experimental online survey to the general Norwegian public. Experimental elements could be presented by manipulating text, images or video. Likely manipulations are seat orientation, presence of a steward, number of passengers present, and safety measures such as emergency stop buttons. Results & Conclusions The study is ongoing, results will be available at the conference. Analyses will focus on exploring the role of the social situation in acceptance of AS. We will seek to experimentally test factors from the MAVA, and how this relates to other theoretical constructs that explore the social situation. The conclusions drawn from this study will impact the integration of autonomous transport systems in Norway and internationally. @en

Background Automated shuttles are tested in many places worldwide. They are typically electrical minibuses operating at SAE level 3 (i.e. with an operator on-board). Low speed, stereotypical driving and compliance with traffic rules characterize their driving. Their software models are able to solve pre-defined traffic situations. However, in situations they have not been trained for, the shuttles might react in unexpected ways. Both predictable and non-predictable reactions of shuttles have impact on human behavior towards them and may affect traffic safety. As safety is a major concern for society and for implementation of automated vehicles, it is essential to understand the safety consequences of human-shuttle interactions. Method This study utilizes video clips of human-shuttle interactions in regular, mixed traffic. Videos were captured in the Oslo region within several TØI projects, at locations such as a shared space, residential areas or signalized intersections. The analyses were conducted in several steps. First, video clips were categorized by a road safety researcher (based on variables such as location and type of involved traffic participants and their maneuvers). Second, a team of experts with diverse backgrounds (such as traffic psychology, game theory, traffic conflict studies, accident analyses, behavioral observations) evaluated the interactions and discussed human behavior towards the shuttles. Utilizing various perspectives of the team members enabled us to better identify the contributory factors to humans’ responses to automated shuttles and to evaluate potential safety issues. Results This study is currently on-going. We identified two major categories of human responses. The first category is characterized by misusing the shuttles’ operational characteristics, e.g., drivers and cyclists overtaking slow shuttles in a risky matter or not giving way to the shuttles. The second category is connected to misinterpreting/not trusting shuttles’ reactions which can result for example in drivers wrongly giving way to the shuttles. Conclusions The preliminary results suggest that an introduction of automated shuttles into urban traffic leads to several types of behavioral adaptations, which can affect the traffic safety. Misusing of shuttles’ operational characteristics and misinterpreting of shuttles’ reactions contribute to the occurrence of these adaptations.@en

Automated shuttles are already seeing deployment in many places across the world and have the potential to transform public mobility to be safer and more accessible. During the current transition phase from fully manual vehicles toward higher degrees of automation and resulting mixed traffic, there is a heightened need for additional communication or external indicators to comprehend automated vehicle actions for other road users. In this work, we present and discuss the results from seven studies (three preparatory and four main studies) conducted in three European countries aimed at investigating and providing a variety of such external communication solutions to facilitate the exchange of information between automated shuttles and other motorized and non-motorized road users.@en

Introduction: Increasing numbers of deployment projects of automated shuttles have been taking place worldwide. Safety is one of the main concerns for their successful implementation. Therefore, it is vital to gain the knowledge about interactions between these shuttles and other traffic participants. Method: Given the lack of behavioural observational studies under regular traffic conditions, the presented study applies external video recordings to explore encounters between the shuttles approaching a T-intersection and other traffic participants. The encounters of interest included a vulnerable road user in the bicycle lane, a pedestrian on the zebra crossing and a road user overtaking the shuttle. The shuttles were identified from the video by RUBA software. We analysed the encounters using T-Analyst software together with the manual observation of traffic participants' behaviour. Results: From 220 h of video, 318 unique manoeuvres of the shuttle were observed and 83 encounters with other traffic participants were identified and explored. Several types of risks and behavioural patterns were identified, such as road users misusing the defensive style of the shuttles or cyclists in the bicycle lane not being sure about the shuttle’s intention. Frequent hard stops of the shuttles might be dangerous for the passengers inside and can increase the risk of rear end accidents. Conclusions: The findings provide a valuable insight into the interactions between automated shuttles and other traffic participants under regular traffic conditions on one location in Oslo, Norway. The study showed that introducing automated shuttles into regular traffic can lead to the emergence of new types of interactions between the shuttles and other traffic participants.

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Automated driving systems promise a tremendous amount of benefits. Especially when applied in the domain of public transport, economic and passenger advantages are thought to be manifold. As technology rapidly advances, and projects involving automated buses appear throughout the world, investigating how its users and surrounding road traffic interact with these novel technologies need to advance with a similar pace. However, up to now, a reliable and up-to-date overview of performed, running, and planned projects is lacking. Moreover, little is known about human interaction with automated bus systems, and what is known is not always reported. By means of a systematic review, an overview of the current state-of-the-art knowledge on the interaction between automated bus systems and its interactors is presented. Results of these studies are described and discussed, and implications are being made regarding future policies to be applied in this domain to safeguard safe interaction with automated bus systems.

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