Pedestrian distraction from Smartphones: An end-user perspective on current and future countermeasures

Pedestrian distraction from smartphone use is a concern from a road safety perspective. This research examined the effectiveness of current and future potential countermeasures from an end-user perspective by means of interviews and a focus group with smartphone users. Four broad countermeasure categories were identified from a countermeasures review: behavioural; legislation/regulation; infrastructure initiatives and technology advances. Overall it was found that no single countermeasure category was perceived by end-users to be fully effective in removing the road safety risk of smartphone use by pedestrians, but rather an integrated approach that combines elements such as pedestrian infrastructure separation, publicity, legislation and a shared responsibility for safety amongst all road users, was deemed to be the most promising solution. Future work in this area, particularly focusing on countermeasure prioritisation and subsequent deployment, is then outlined.     

A systematic review of observational studies investigating the influence of mobile phone distraction on road crossing behaviour of pedestrians

The growing prevalence of technological distractions amongst pedestrians makes it an important road safety concern. Observational studies are considered a reliable method to investigate the influence of mobile phone distraction on pedestrian road crossing behaviour and crash risks. The present study conducts a systematic review of international literature on pedestrian distraction observations by following the Preferred Reporting Items for Systematic Reviews and meta-Analyses (PRISMA) guidelines. A total of 792 studies were identified from the literature search on six research databases: Scopus, Google Scholar, Web of Science, PubMed, Cochrane library, and Transportation Research International Documentation (TRID). Finally, 39 research articles were assessed using the systematic classification scheme based on the following five research aspects: prevalence of mobile phone distraction, study locations, performance measures, analysis techniques, and additional factors associated with mobile phone use among pedestrians. Over 35% of the studies were conducted in the United States of America (USA) and 69% of the investigations were done in the last five years. Overall, the findings across the studies indicate that mobile phone distraction plays a major role in pedestrian risky road crossing behaviour and violation tendencies. Visual distractions (such as texting) exhibited higher behavioural impairment compared to cognitive distractions (e.g., listening to music, and conversations). Pedestrian characteristics such as gender and age were the key factors examined in 77% and 67% of the observational studies. Finally, important directions for future research are illustrated to aid the researchers working in the area of pedestrian safety.     

Stream segregation revisited: Dynamic listening and influences of emotional context on stream perception and attention

A classical experiment of auditory stream segregation is revisited, reconceptualising perceptual ambiguity in terms of affordances and musical engagement. Specifically, three experiments are reported that investigate how listeners’ perception of auditory sequences change dynamically depending on emotional context. The experiments show that listeners adapt their attention to higher or lower pitched streams (Experiments 1 and 2) and the degree of auditory stream integration or segregation (Experiment 3) in accordance with the presented emotional context. Participants with and without formal musical training show this influence, although to differing degrees (Experiment 2). Contributing evidence to the literature on interactions between emotion and cognition, these experiments demonstrate how emotion is an intrinsic part of music perception and not merely a product of the listening experience.     

The effect of gender on the N1-P2 auditory complex while listening and speaking with altered auditory feedback

The effect of gender on the N1-P2 auditory complex was examined while listening and speaking with altered auditory feedback. Fifteen normal hearing adult males and 15 females participated. N1-P2 components were evoked while listening to self-produced nonaltered and frequency shifted /a/ tokens and during production of /a/ tokens during nonaltered auditory feedback (NAF), frequency altered feedback (FAF), and delayed auditory feedback (DAF; 50 and 200 ms). During speech production, females exhibited earlier N1 latencies during 50 ms DAF and earlier P2 latencies during 50 ms DAF and FAF. There were no significant differences in N1-P2 amplitudes across all conditions. Comparing listening to active speaking, N1 and P2 latencies were earlier among females, with speaking, and under NAF. N1-P2 amplitudes were significantly reduced during speech production. These findings are consistent with the notions that speech production suppresses auditory cortex responsiveness and males and females process altered auditory feedback differently while speaking.     

Audiovisual time-to-collision estimation for accelerating vehicles: The acoustic signature of electric vehicles impairs pedestrians' judgments

To avoid collisions, pedestrians intending to cross a road need to accurately estimate the time-to-collision (TTC) of an approaching vehicle. For TTC estimation, auditory information can be considered particularly relevant when the approaching vehicle accelerates. The sound of vehicles with internal combustion engine (ICEVs) provides characteristic auditory information about the acceleration state (increasing rotational speed and engine load). However, for electric vehicles (EVs), the acoustic signature during acceleration is less salient. Although the auditory detection of EVs has been studied extensively, there is no research on potential effects of the altered acoustic signature of EVs on TTC estimation. To close this gap, we compared TTC estimates for ICEVs and for EVs with and without activated acoustic vehicle alerting system (AVAS). We implemented a novel interactive audiovisual virtual-reality system for studying the human perception of approaching vehicles. Using acoustic recordings of real vehicles as source signals, the dynamic spatial sound field corresponding to a vehicle approaching in an urban setting is generated based on physical modeling of the sound propagation between vehicle and pedestrian (listener) and is presented via sound field synthesis (higher-order Ambisonics). In addition to the auditory simulations, the scene was visually presented on a head-mounted display with head tracking. Participants estimated the TTC of vehicles that either approached at a constant speed or accelerated positively. In conditions with constant speed, TTC estimates for EVs with and without AVAS were similar to those for ICEVs. In contrast, for accelerating vehicles, there was a substantial effect of the vehicle type on the TTC estimates. For the EVs, the mean TTC estimates showed a significant overestimation. Thus, subjects on average perceived the time of arrival of the EV at their position as longer than it actually was. The extent of overestimation increased with acceleration and presented TTC. This pattern is similar to a first-order TTC estimation representing a failure to consider the acceleration, which is consistently reported in the literature for visual-only presentations of accelerating objects. In comparison, the overestimation of TTC was largely reduced for the accelerating ICEVs. The AVAS somewhat improved the TTC estimates for the accelerating EVs, but without reaching the same level of accuracy as for the ICEVs. In real traffic scenarios, overestimations of the TTC of approaching vehicles might lead to risky road-crossing decisions. Therefore, our finding that pedestrians are significantly less able to use the acoustic information emitted by accelerating EVs for their TTC judgments, compared to accelerating ICEVs, has important implications for road safety and for the design of AVAS technologies.     

事件提示和时间提示对新异干扰的影响—— 来自听视跨通道和听通道的证据

采用Oddball范式考察听视跨感觉通道和听感觉通道中“无关刺激”或“无关属性”的信号提示对新异干扰的影响。实验1和实验2分别比较了听视跨通道和听通道中时间事件提示、时间提示和事件提示三种条件。结果表明：(1)时间提示条件下新异干扰效应消失, 而事件提示条件下新异干扰效应仍存在。无关刺激意外变化引起的靶任务行为受损, 不仅与偏差刺激的小概率和新颖性有关, 而且与干扰刺激与靶子间提示信号关联有关, 这种提示关联中事件发生的提示功能比时间间隔的提示功能更为重要。(2)听通道下新异干扰与视听跨通道结果一致, 无关属性也会起到提示信号作用, 同样事件提示功能比时间提示功能更重要。     

Perspectives on dichotic listening and the corpus callosum

The present review summarizes historic and recent research which has investigated the role of the corpus callosum in dichotic processing within the context of audiology. Examination of performance by certain clinical groups, including split brain patients, multiple sclerosis cases, and other types of neurological lesions is included. Maturational, age related, and genetic factors are also discussed. Finally, some attention is given to recent trends in audiology research to develop improved diagnostic and rehabilitation tools for individuals with dichotic deficits potentially related to callosal dysfunction.     

Interaction between pedestrians and automated vehicles: A Wizard of Oz experiment

Automated vehicles (AVs) will be introduced on public roads in the future, meaning that traditional vehicles and AVs will be sharing the urban space. There is currently little knowledge about the interaction between pedestrians and AVs from the point of view of the pedestrian in a real-life environment. Pedestrians may not know with which type of vehicle they are interacting, potentially leading to stress and altered crossing decisions. For example, pedestrians may show elevated stress and conservative crossing behavior when the AV driver does not make eye contact and performs a non-driving task instead. It is also possible that pedestrians assume that an AV would always yield (leading to short critical gaps). This study aimed to determine pedestrians’ crossing decisions when interacting with an AV as compared to when interacting with a traditional vehicle. We performed a study on a closed road section where participants (N = 24) encountered a Wizard of Oz AV and a traditional vehicle in a within-subject design. In the Wizard of Oz setup, a fake ‘driver’ sat on the driver seat while the vehicle was driven by the passenger by means of a joystick. Twenty scenarios were studied regarding vehicle conditions (traditional vehicle, ‘driver’ reading a newspaper, inattentive driver in a vehicle with “self-driving” sign on the roof, inattentive driver in a vehicle with “self-driving” signs on the hood and door, attentive driver), vehicle behavior (stopping vs. not stopping), and approach direction (left vs. right). Participants experienced each scenario once, in a randomized order. This allowed assessing the behavior of participants when interacting with AVs for the first time (no previous training or experience). Post-experiment interviews showed that about half of the participants thought that the vehicle was (sometimes) driven automatically. Measurements of the participants’ critical gap (i.e., the gap below which the participant will not attempt to begin crossing the street) and self-reported level of stress showed no statistically significant differences between the vehicle conditions. However, results from a post-experiment questionnaire indicated that most participants did perceive differences in vehicle appearance, and reported to have been influenced by these features. Future research could adopt more fine-grained behavioral measures, such as eye tracking, to determine how pedestrians react to AVs. Furthermore, we recommend examining the effectiveness of dynamic AV-to-pedestrian communication, such as artificial lights and gestures.     

Behavioural analysis of interactions between pedestrians and vehicles in street designs with elements of shared space

This paper describes the development and implementation of qualitative behavioural criteria in order to analyse the conduct of pedestrians and vehicles when they are required to interact with each other, with particular interest to street designs with elements of shared space. The new behavioural analysis technique is developed by identifying the fundamental principles that underpin existing traffic analyses, such as traffic conflicts techniques, and adapting those to a qualitative framework that describes the mindset and rationale of road users. The technique is then applied to a case study in London, using video data from periods before and after the redevelopment of the Exhibition Road site from a conventional dual carriageway to a modern design with some elements of shared space. With the main goals being to assess the pedestrians’ confidence and the vehicles’ tolerance/patience when forced to interact with each other, behavioural trends are related to instantaneous characteristics of the vehicle flow (vehicle approach speed and traffic density). The data produced are used to develop and validate qualitative behavioural relationships for pedestrian–vehicle interactions, as well as location-specific conclusions for the Exhibition Road site.     

Sharing the road with autonomous vehicles: A qualitative analysis of the perceptions of pedestrians and bicyclists

Public perception assessment is important for gaining a better understanding of the acceptance of autonomous vehicles (AVs) and identifying potential ways to resolve public concerns. This study investigated how pedestrians and bicyclists perceived AVs based on their knowledge and road sharing experiences, applying a combined inductive and deductive data analysis approach. Survey responses of pedestrians and bicyclists in Pittsburgh, Pennsylvania, USA collected by Bike Pittsburgh (BikePGH) in 2019, were analyzed in this research. AVs following traffic rules appropriately and AVs driving safer than the human drivers were the most notable positive perceptions towards AVs. Pedestrians and bicyclists showed comparatively fewer negative perceptions towards AVs than positive perceptions. Negative perceptions mostly included a lack of perceived safety and comfort around AVs and trust in the AV technology. Respondents also concerned about AV technology issues (e.g., slow and defensive driving, disruptive maneuver), while sharing the road with AVs. Perceptions of the respondents were significantly influenced by their views on AV safety, familiarity with the technology, the extent respondents followed AV on the news, and household automobile ownership. Regulating AV movement on roadways, developing safety assessment guidelines, and controlling oversights of improper practices by AV companies were the major suggestions from the survey participants. Findings of this study might help AV companies to identify potential improvement needed in AV technology to increase pedestrians and bicyclists acceptance, and policymakers to develop policy guidelines to ensure safe road sharing among pedestrians, bicyclists, and AVs.     

Psychological and psychophysiological effects of music intensity and lyrics on simulated urban driving

The main aim of this study was to investigate the effect of musical characteristics (i.e., presence of lyrics and loudness) in the context of simulated urban driving. Previous work has seldom isolated musical characteristics and examined these both singularly and interactively. We investigated the potentially distracting effects of processing lyrics through exposing young drivers to the same piece of music with/without lyrics and at different sound intensities (60 dBA [soft] and 75 dBA [loud]) using a counterbalanced, within-subjects design (N = 34; M_age = 22.2 years, SD = 2.0 years). Six simulator conditions were included that comprised low-intensity music with/without lyrics, high-intensity music with/without lyrics, plus two controls – ambient in-car noise and spoken lyrics. Between-subjects variables of driving style (defensive vs. assertive) and sex (women vs. men) were explored. A key finding was that the no lyrics/soft condition yielded lower affective arousal scores when compared to the other music conditions. There was no main effect of condition for HRV data (SDNN and RMSSD). Exploratory analyses showed that, for assertive drivers, NASA-TLX Performance scores were lower in the no lyrics/soft condition compared to the lyrics/loud condition. Moreover, women exhibited higher mean heart rate than men in the presence of lyrics. Although some differences emerged in subjective outcomes, these were not replicated in HRV, which was used as an objective index of emotionality. Drivers should consider the use of soft, non-lyrical music to optimise their affective state during urban driving.     

The content of the message influences the hand choice in co-speech gestures and in gesturing without speaking

The present study investigates the hand choice in iconic gestures that accompany speech. In 10 right-handed subjects gestures were elicited by verbal narration and by silent gestural demonstrations of animations with two moving objects. In both conditions, the left-hand was used as often as the right-hand to display iconic gestures. The choice of the right- or left-hands was determined by semantic aspects of the message. The influence of hemispheric language lateralization on the hand choice in co-speech gestures appeared to be minor. Instead, speaking seemed to induce a sequential organization of the iconic gestures.     

Intentional attention switching in dichotic listening: Exploring the efficiency of nonspatial and spatial selection

Using an auditory variant of task switching, we examined the ability to intentionally switch attention in a dichotic-listening task. In our study, participants responded selectively to one of two simultaneously presented auditory number words (spoken by a female and a male, one for each ear) by categorizing its numerical magnitude. The mapping of gender (female vs. male) and ear (left vs. right) was unpredictable. The to-be-attended feature for gender or ear, respectively, was indicated by a visual selection cue prior to auditory stimulus onset. In Experiment 1, explicitly cued switches of the relevant feature dimension (e.g., from gender to ear) and switches of the relevant feature within a dimension (e.g., from male to female) occurred in an unpredictable manner. We found large performance costs when the relevant feature switched, but switches of the relevant feature dimension incurred only small additional costs. The feature-switch costs were larger in ear-relevant than in gender-relevant trials. In Experiment 2, we replicated these findings using a simplified design (i.e., only within-dimension switches with blocked dimensions). In Experiment 3, we examined preparation effects by manipulating the cueing interval and found a preparation benefit only when ear was cued. Together, our data suggest that the large part of attentional switch costs arises from reconfiguration at the level of relevant auditory features (e.g., left vs. right) rather than feature dimensions (ear vs. gender). Additionally, our findings suggest that ear-based target selection benefits more from preparation time (i.e., time to direct attention to one ear) than gender-based target selection.     

Contextual influences on phonetic identification in aphasia: the effects of speaking rate and semantic bias

Two experiments examined the influence of context on stop-consonant voicing identification in fluent and nonfluent aphasic patients and normal controls. Listeners were required to label the initial stop in a target word varying along a voice onset time (VOT) continuum as either voiced or voiceless ([b]/[p] or [d]/[t]). Target stimuli were presented in sentence contexts in which the rate of speech of the sentence context (Experiment 1) or the semantic bias of the context (Experiment 2) was manipulated. The results revealed that all subject groups were sensitive to the contextual influences, although the extent of the context effects varied somewhat across groups and across experiments. In addition, a number of patients in both the fluent and nonfluent aphasic groups could not consistently identify even endpoint stimuli, confirming phonetic categorization impairments previously shown in such individuals. Results are discussed with respect to the potential reliance by aphasic patients on higher level context to compensate for phonetic perception deficits.     

Effects of attention on dichotic listening in elderly and patients with dementia of the Alzheimer type

This article presents an overview of our studies in elderly and Alzheimer patients employing Kimura's dichotic digits paradigm as a measure for left hemispheric predominance for processing language stimuli. In addition to structural brain mechanisms, we demonstrated that attention modulates the direction and degree of ear asymmetry in dichotic listening. Elderly showed increasingly more difficulties focusing attention on the left ear (LE) with advancing age. Alzheimer patients showed severe deficits to allocate attention to the LE, which could result in a right ear advantage. These results may be attributed to a breakdown of the cortical attentional network which is mediated by frontal (inhibitory control of attention) and parietal regions (spatial attention and 'disengagement processes'). Both interhemispheric disconnectivity (callosal atrophy) and intrahemispheric disconnectivity (subcortical white matter lesions) appear to be important factors contributing to these findings.     

Contextual influences on the internal structure of phonetic categories: A distinction between lexical status and speaking rate

Previous research has shown that phonetic categories have a graded internal structure that is highly dependent on acoustic-phonetic contextual factors, such as speaking rate; these factors alter not only the location of phonetic category boundaries, but also the location of a category’s best exemplars. The purpose of the present investigation, which focused on the voiceless category as specified by voice onset time (VOT), was to determine whether a higher order linguistic contextual factor, lexical status, which is known to alter the location of the voiced—voiceless phonetic category boundary, also alters the location of the best exemplars of the voiceless category. The results indicated that lexical status has a more limited and qualitatively different effect on the category’s best exemplars than does the acousticphonetic factor of speaking rate. This dissociation is discussed in terms of a production-based account in which perceived best exemplars of a category track contextual variation in speech production.     

Contextual influences on the internal structure of phonetic categories: a distinction between lexical status and speaking rate

Previous research has shown that phonetic categories have a graded internal structure that is highly dependent on acoustic-phonetic contextual factors, such as speaking rate; these factors alter not only the location of phonetic category boundaries, but also the location of a category's best exemplars. The purpose of the present investigation, which focused on the voiceless category as specified by voice onset time (VOT), was to determine whether a higher order linguistic contextual factor, lexical status, which is known to alter the location of the voiced-voiceless phonetic category boundary, also alters the location of the best exemplars of the voiceless category. The results indicated that lexical status has a more limited and qualitatively different effect on the category's best exemplars than does the acoustic-phonetic factor of speaking rate. This dissociation is discussed in terms of a production-based account in which perceived best exemplars of a category track contextual variation in speech production.     

The impact of a child bike seat and trailer on the objective overtaking behaviour of motorized vehicles passing cyclists

IntroductionThe lateral clearance distance of a motorized vehicle while overtaking a cyclist is a key indicator of safety. This lateral clearance distance has never been measured for cyclists transporting a child. Therefore the aim of this study was to investigate the behaviour of motorized vehicles in overtaking cyclists with and without a child on the same bicycle.MethodsThe lateral clearance distance of the overtaking manoeuvres of motorized vehicles was measured using an instrumented bicycle when performing 19 cycling trips on one single road with two different types of cycling infrastructure (a bike lane and shared lane marking) in the Brussels Capital Region (Belgium). Mixed effect regression was used to examine the effect of cycling condition (cyclist without a child [control], cyclist with a child bike seat and cyclist with a child bike trailer) and secondary independent variables (i.e. cycling infrastructure, peak traffic hours and traffic density) on the lateral clearance distance.ResultsThe mean lateral clearance distance in ‘cyclists without child’ was significantly smaller (117.3 cm) than in ‘cyclists with child’ (128.8 cm) (95%CI [7.2;15.9]). Looking at ‘morning peak traffic hours’ (i.e. 7:00 to 9:00 a.m.) a cyclist with child bike seat was overtaken at greater lateral clearance distances than a cyclist with a child bike trailer or a cyclist without child (p=0.041). Furthermore, the percentage of passing manoeuvres under 100 cm was significantly higher in ‘cyclist without child’ (35.3%) in comparison to ‘cyclist with child bike seat’ (21.8%) and ‘cyclist with child bike trailer’ (21.8%) (Chi2=29.19, p<0.001). No significant differences were found between a shared lane marking and bike lane.ConclusionDrivers of motorized vehicles do adapt their overtaking manoeuvre when they overtake cyclists transporting a child, keeping greater and therefore safer lateral clearance distances. In morning peak traffic hours and/or crowded circumstances the child bike seat can be considered as the safest way to transport a child in terms of lateral clearance distance. In general, with 25.3% overtaking manoeuvres under 100cm, police should monitor compliance with the traffic rules with regard to cyclists, and motorists should be more aware of the overtaking traffic rules.     

Expert athletes activate somatosensory and motor planning regions of the brain when passively listening to familiar sports sounds

The present functional magnetic resonance imaging study examined the neural response to familiar and unfamiliar, sport and non-sport environmental sounds in expert and novice athletes. Results revealed differential neural responses dependent on sports expertise. Experts had greater neural activation than novices in focal sensorimotor areas such as the supplementary motor area, and pre- and postcentral gyri. Novices showed greater activation than experts in widespread areas involved in perception (i.e. supramarginal, middle occipital, and calcarine gyri; precuneus; inferior and superior parietal lobules), and motor planning and processing (i.e. inferior frontal, middle frontal, and middle temporal gyri). These between-group neural differences also appeared as an expertise effect within specific conditions. Experts showed greater activation than novices during the sport familiar condition in regions responsible for auditory and motor planning, including the inferior frontal gyrus and the parietal operculum. Novices only showed greater activation than experts in the supramarginal gyrus and pons during the non-sport unfamiliar condition, and in the middle frontal gyrus during the sport unfamiliar condition. These results are consistent with the view that expert athletes are attuned to only the most familiar, highly relevant sounds and tune out unfamiliar, irrelevant sounds. Furthermore, these findings that athletes show activation in areas known to be involved in action planning when passively listening to sounds suggests that auditory perception of action can lead to the re-instantiation of neural areas involved in producing these actions, especially if someone has expertise performing the actions.     

Reading the road: The influence of age and sex on child pedestrians' perceptions of road risk

The United Kingdom has one of the highest records of child pedestrian accidents in the European Union, and statistics show boys are particularly vulnerable. This study investigated whether there were identifiable developmental or sex differences in the perception of road risk, which might explain the occurrence of such child pedestrian accidents. The study was a between‐participants experimental design with three independent variables: age, sex and task. The sample comprised 119 school children in three age groups (7–8 years; 9–10 years and 11–12 years) with equal sex distribution in each age group. All children, tested individually, completed two sorting tasks. The tasks differed in that children first classified 20 photographs of road scenes on self‐selected criteria (free sort) and then reclassified the scenes on the basis of safety of each scene (cued sort). When children operated a free sort, age differences were apparent in both the number and type of categories produced. However, this age variation was not apparent for the cued sort showing that the younger children were strongly influenced by cueing. Younger children exhibited a more personal and idiosyncratic perspective of the road compared to older children, who were able to view the road from global perspectives. Sex differences in assessing safety were limited but interesting, demonstrating that the males focussed on physical attributes of the scene and females on the actors within the scene. The focus of females on the dynamic attributes of the scene may be a partial explanation of their greater safety record compared to their male peers.