The estimation of vehicle speed and stopping distance by pedestrians crossing streets in a naturalistic traffic environment

The ability to estimate vehicle speed and stopping distance accurately is important for pedestrians to make safe road crossing decisions. In this study, a field experiment in a naturalistic traffic environment was conducted to measure pedestrians’ estimation of vehicle speed and stopping distance when they are crossing streets. Forty-four participants (18–45 years old) reported their estimation on 1043 vehicles, and the corresponding actual vehicle speed and stopping distance were recorded. In the speed estimation task, pedestrians’ performances change in different actual speed levels and different weather conditions. In sunny conditions, pedestrians tended to underestimate actual vehicle speeds that were higher than 40 km/h but were able to accurately estimate speeds that were lower than 40 km/h. In rainy conditions, pedestrians tended to underestimate actual vehicle speeds that were higher than 45 km/h but were able to accurately estimate speeds ranging from 35 km/h to 45 km/h. In stopping distance estimation task, the accurate estimation interval ranged from 60 km/h to 65 km/h, and pedestrians generally underestimated the stopping distance when vehicles were travelling over 65 km/h. The results show that pedestrians have accurate estimation intervals that vary by weather conditions. When the speed of the oncoming vehicle exceeded the upper bound of the accurate interval, pedestrians were more likely to underestimate the vehicle speed, increasing their risk of incorrectly deciding to cross when it is not safe to do so.     

Illegal crossing behavior of pedestrians at signalized intersections: Factors affecting the gap acceptance

Purpose of designing crosswalks is to allow pedestrians to cross the roads safely avoiding conflicts between pedestrians and motorized vehicles. However, pedestrians do not always comply with the crossing rules, whether it is timing (signalization) and/or location (crossing facility). An observation survey of illegal crossings was conducted at six intersections in Izmir, Turkey to determine the distance and time gap perception of the pedestrians for safe road-crossing within the 25 m of the crosswalk. Each intersection was observed on weekdays during afternoon (12.30–13.30) and evening peak hours (17.00–18.00). Totally, 444 illegal crossings were observed at all intersections. Data were analyzed playing the video recordings in office. All roads were consisted of two lanes. In this study pedestrians’ illegal crossing behavior at signalized intersections depending on the position of the oncoming vehicle is of interest. Safety margins and crossing times of the pedestrians were also reported. Position of the vehicle was determined for the first lane at the instant the pedestrian stepped the lane. Pedestrians’ distance gap perception was categorized into five groups depending on the position of the oncoming vehicle which are; vehicle is within the 25 m of the crosswalk, vehicle is within the 25–50 m of the crosswalk, vehicle is within the 50–75 m of the crosswalk, vehicle is just beyond 75 m, and vehicle is out of field of view. Factors affecting the distance gaps, safety margins and crossing times were analyzed by ANOVA. The most significant effect was the vehicle speed in all analysis. Pedestrians based their decision of crossing on distance rather than time gap.     

Two-step communication for the interaction between automated vehicles and pedestrians

An important challenge of automated vehicles (AV) will be the cooperative interaction with surrounding road users such as pedestrians. One solution to compensate for the missing driver-pedestrian interaction might be explicit communication via external human machine interfaces (eHMIs). Additionally, implicit communication such as a vehicle pitch motion might support AVs when interacting with pedestrians. While previous work explored various explicit and implicit communication cues, these concepts communicated the intention of the AV at one single time point. Currently, empirical findings on two-step communication lack so far. In this study, we empirically test the effect of a two-step AV communication that uses an implicit cue at a long distance and subsequently provides an implicit or explicit cues at a short distance. We compared its efficiency to single-step communication concepts providing implicit or explicit cues at the shorter distance only. To explore whether the right communication cue is used at the right distance, we analyzed pedestrians’ fixations while approaching an AV using an eye tracking device.We conducted a virtual reality study (N = 30) with AV communication concept that provided an active pitch motion or an eHMI and compared them with a two-step AV communication concept that provided an additional active pitch motion at a long distance when approaching the pedestrian. Furthermore, we recorded pedestrians’ fixation behavior while the AV approached.Consistently to previous work, single-step AV communication showed a beneficial effect on crossing behavior. Pedestrians initiated their crossing earlier while approaching an AV with an active pitch motion or an eHMI compared to the baseline condition. While active pitch motion reduced subjective safety feeling, eHMI increased it. However, the two-step communication concept did not further improve pedestrians’ crossing initiation times and their safety feeling. The pattern of fixation behavior differed as a function of AV distance. When the approaching AV was far away, pedestrians exclusively looked at the environment. During the approach, pedestrians gradually fixated the bumper and the hood and only then the windshield of the AV. Hence, it seems to be useful to present an AV intent communication at a certain distance from the pedestrian. These findings posit the importance of considering pedestrians’ fixation behavior when developing communication concepts between AVs and pedestrians.     

Analyzing pedestrian behavior when crossing urban roads by combining RP and SP data

Considering the high crash rates involving pedestrians on urban roads, it is highly relevant to understanding pedestrian crossing behavior. This paper is the first to combine stated preference (SP) and revealed preference (RP) data to evaluate the impact that individual attributes, trip characteristics, built environment, strategies to prevent unauthorized crossing, and traffic flows have on pedestrians crossing decisions in an urban context. SP and RP surveys were designed and collected in Barranquilla (Colombia) near pedestrian bridges or signalized intersections where direct crossings and a high concentration of pedestrian fatalities related to traffic accidents exist. A logit model was estimated using the data enrichment paradigm. Results show that pedestrians weigh risks and costs when choosing how to cross the road. The trajectories observed in the RP component suggest that people prefer direct crossings; nevertheless, pedestrian bridges and signalized intersections can be attractive alternatives if their location matches the origin or destination of the crossing, and no detour is needed to use them. Waiting time; safety; the fine imposed for jaywalking; personal security, and previous decisions are also variables that influence pedestrian behavior when crossing urban roads. These results can be helpful to urban planners and decision-makers interested in proposing appropriate pedestrian infrastructure. The data pooling technique and the inclusion of a cost-related variable (i.e., fine) allowed computing the willingness to pay and marginal substitution rates for attributes of the built environment and other characteristics associated with the crossing decision. Also, the inclusion of several crossing alternatives and situations allowed assessing pedestrian crossing preferences under different scenarios.     

A method in modeling interactive pedestrian crossing and driver yielding decisions during their interactions at intersections

Investigating pedestrian crossing and driver yielding decisions should be an important focus considering the high risks of pedestrians in exposed to motorized traffic. Limitations, however, exist in previous studies – variables considered previously have been limited; how their behavior affect each other (defined as interactive impacts) were not sufficiently considered. This paper aims to provide a methodological approach for pedestrian crossing and driver yielding decisions during their interactions, considering of different variable types including interactive impact variables, traffic condition variables, road design variables, and environment variables. A Distance-Velocity (DV) framework proposed in an earlier study is introduced for definitions and concepts in studying pedestrian-vehicle interactions. Logistic regression, support vector machines, neural networks and random forests, are introduced as candidate models. A case study involving six crosswalk locations is conducted, focusing on interactions between pedestrians and right-turn vehicles. The proposed methodological approach is applied, with the performance of the four machine learning methods compared in terms of model generalization and confusion matrix. The model with the best performance is further compared to the typical gap-based model. Results show that random forest and logistic regression models performed the best in modeling pedestrian crossing and driver yielding decisions respective, in terms of model generalization. Besides, the DV-based modeling method (average accuracy of over 90% for pedestrians and 80% for drivers) outperformed the traditional gap-based method in all test seeds. As a key finding, interactive impacts from each other (the pedestrian and the driver) act as a key contributing variable on their decisions.     

Behavior model and guidance strategies of the crossing behavior at unsignalized intersections in the connected vehicle environment

The connected vehicle environment is considered to be a disruptive technology that reconstructs the way people travel and road transport, and more importantly, ensures traffic safety. This study aims on investigating drivers’ interactive behavior at an unsignalized intersection in the connected vehicle environment. Specifically, a simplified iterative behavior model was established to predict the potential conflicting vehicles’ behavior. Furthermore, based on principles of safety, efficiency, and comfort, the guidance strategies were proposed to help the subject vehicles cross intersections. A multi-user driving simulator experiment was carried out and 48 participants were divided into 24 pairs to complete the test. The simplified iterative behavior model was constructed based on the dynamic interaction of each participant pair as they approached the intersection from straight-crossing directions. The comparison results showed the behavior model was an effective microscopic simulation tool for vehicles at unsignalized intersections with high accuracy and good applicability. Then, the guidance strategies under different compliance rates (baseline, 50 % compliance, 100% compliance) were evaluated based on three indexes i.e. standard deviation of speed (SDS), duration of crossing the intersection (DCI), and time exposed post-encroachment-time (TEP). The numerical simulation results showed that the guidance strategies could effectively improve the safety and efficiency of drivers crossing the intersection under both 50% and 100% compliance rates. Besides, with the increase of compliance rate, the comfort level also increased evidently. This study can provide theoretical and algorithmic references for microscopic simulation and guidance strategy at unsignalized intersections in the connected vehicle environment.     

Treatment effectiveness of PMTO for children's behavior problems in Iceland: Assessing parenting practices in a randomized controlled trial

Findings are presented from an Icelandic randomized control trial (RCT) evaluating parent management training – Oregon model (PMTO?), a parent training intervention designed to improve parenting practices and reduce child behavior problems. In a prior report from this effectiveness study that focused on child outcomes, children in the PMTO condition showed greater reductions in reported child adjustment problems relative to the comparison group. The present report focuses on observed parenting practices as the targeted outcome, with risk by treatment moderators also tested. It was hypothesized that mothers assigned to the PMTO condition would show greater gains in pre‐post parenting practices relative to controls. The sample was recruited from five municipalities throughout Iceland and included 102 participating families of children with behavior problems. Cases were referred by community professionals and randomly assigned to either PMTO (n = 51) or community services usually offered (n = 51). Child age ranged from 5 to 12 years; 73% were boys. Contrary to expectations, findings showed no main effects for changes in maternal parenting. However, evaluation of risk by treatment moderators showed greater gains in parenting practices for mothers who increased in depressed mood within the PMTO group relative to their counterparts in the comparison group. This finding suggests that PMTO prevented the expected damaging effects of depression on maternal parenting. Failure to find hypothesized main effects may indicate that there were some unobserved factors regarding the measurement and a need to further adapt the global observational procedures to Icelandic culture.     

The safety and conspicuity of pedestrian crossing at roundabouts: The effect of median refuge island and zebra markings

Roundabouts are one of the most used road intersections because, compared to signalized ones, they reduce conflict points between traffic flows and moderate driving speed. Great attention should also be paid to vulnerable road users at roundabouts. According to accident statistics, in fact, accessibility of pedestrians and cyclists is not always ensured.This paper has evaluated the effects on the visibility of pedestrian crossing before and after the displacement of zebra markings, moved before intersections, and the introduction of media refuge islands and “Yield here to pedestrians” vertical signs. The above effects have been assessed by before-after analysis of speed and visual behaviour of drivers approaching the crosswalk.Moreover, the analysis of the drivers’ eye movements has highlighted the most salient elements of the pedestrian crossing. The relation between the drivers’ visual behaviour and the vehicle speed have also been calculated. Results have confirmed that the intervention carried out has increased both visibility and safety of the studied pedestrian crosswalks.Zebra markings and the median refuge island have turned out to be the most glanced elements, respectively seen by 93.75% and 56.25% of the drivers, followed by the “Yield here to pedestrians” vertical sign. The mean distance of first fixation of the crosswalk increased from 21.98 m before the intervention, to 40.69 m after it. The drivers perceived the pedestrian crossings from a longer distance after the intervention, and they continued to glance at the crosswalk while approaching it, enhancing their visual attention.     

Assessing Type A behavior in children: a longitudinal exploration of the overlap between Type A behavior and hyperactivity

Child Type A behavior and its relation to hyperactivity were investigated developmentally using a longitudinal normal sample of 91 children (46 boys and 45 girls) between the ages of 4 and 8-9. In light of the overlap found in several studies between Type A behavior, as measured by the Matthews Youth Test for Health (MYTH) questionnaire, and hyperactivity measured by questionnaires, an attempt was made to measure Type A behavior as distinct from hyperactivity using behavioral observations. The MYTH questionnaire and behavioral observations were used to assess Type A behavior and questionnaire-based measures and behavioral observations were used to assess hyperactivity. Predictions were made regarding individual stability in phenomena and in measures. The results indicated considerable stability in the respective Type A and hyperactivity measures over time, and further, that behavioral observations make it possible to measure Global Type A behavior and Type A Competitiveness as distinct from hyperactivity, although the status of Type A Impatience at early ages is not yet settled. The MYTH and the observed Type A behavior showed differential relations to external criteria, such as achievement measures and problem behavior. This has implications for future measurement and perhaps conceptualization of Type A behavior in children, and thereby also for studying the developmental aspects of Type A behavior.     

Assessing potential effects of daily cross-domain usage of information and communication technologies

ABSTRACT

A within-person diary research design with 39 full-time workers was used to examine the effects of daily cross-domain usage of information and communication technologies (ICTs) on job-related performance and stress in both workplace and home domains. Segmentation preference effects on links between cross-domain ICT usage and both job performance and job stress were also analyzed. A positive association was found for the first relationship in mixed home-workplace contexts, and a negative association for the second in home contexts only. A stronger segmentation preference effect on the negative relationship between cross-domain ICT usage and job stress was found for integrators (employees who integrate work and home domains) compared to separators (employees who separate work/non-work activities). Our findings suggest that daily cross-domain ICT usage can enhance job performance and reduce job stress, with a moderating effect of segmentation preference on the link between cross-domain ICT usage and job stress.     

家中不同游戏情境中婴儿与父母交流行为的比较研究

采用录像手段,考察真实的家庭环境中,16名婴儿与父亲和母亲在自由游戏和完成任务游戏情境中的交流行为。研究结果表明,无论在自由游戏还是在完成任务游戏中,母亲的表态行为都比父亲的多些。婴儿对母亲的表态行为比对父亲的多,对父亲的行动祈求、信息祈求和注意祈求行为比对母亲的多。在自由游戏中,母亲比父亲更多地承诺参与儿童的游戏。总体上,父母亲根据交流情境选择交流行为外,也表现出自身的特点,孩子则根据交流对象的选择交流行为。     

Comparison of single and multiple functional communication training responses for the treatment of problem behavior

Two functional communication training (FCT) conditions without extinction were compared to treat the problem behavior of a child with developmental disabilities. The individual was taught to emit a single FCT response to obtain one of six items delivered in a randomized order or multiple FCT responses that specified the exact item. Results showed that only the FCT-multiple condition reduced problem behavior and maintained alternative mands.     

An exploration of common dopaminergic variants and behavior problems in siblings at high risk for autism spectrum disorder

Younger siblings of children with ASD often exhibit elevated internalizing and externalizing problems. We investigated common dopaminergic variants (DRD4 and DRD2) in relation to behavior problems at 36 months. Genotypes linked to less efficient dopaminergic functioning were associated with higher internalizing problems in high-risk siblings.     

Impact of time pressure on acceleration behavior and crossing decision at the onset of yellow signal

This study investigates acceleration behavior and crossing decision of the drivers under increasing time pressure driving conditions. A typical urban route was designed in a fixed-base driving simulator consisting of four signalized intersections with varying time to stop line (4 s and 6 s) and maneuver type (right-turn and go-through). 97 participants’ data were obtained under No Time Pressure (NTP), Low Time Pressure (LTP), and High Time Pressure (HTP) driving conditions. The acceleration behavior was examined at the onset of yellow signal in four ways: continuous deceleration, acceleration-deceleration, deceleration-acceleration, and continuous acceleration. A random forest model was used to build an acceleration behavior prediction model for identifying the significant explanatory variables based on variable importance ranking. Further, a Mixed Effects Multinomial Logit (MEML) model was developed using the explanatory variables obtained from a random forest model. Additionally, a generalized linear mixed model was incorporated for estimating the likelihood of crossing an intersection by considering all the explanatory variables. A MEML model result revealed that the odds of adopting acceleration-deceleration, deceleration-acceleration, and continuous acceleration instead of continuous deceleration increased by 63 %, 123 %, and 77 %, respectively under HTP driving conditions. Moreover, the likelihood of crossing a signalized intersection increased by 2.73 times and 4.26 times when the drivers were under LTP and HTP driving conditions, respectively as compared to NTP driving condition. Apart from this, time to stop line (reference: 6 s) and age showed negative association with crossing probability. Overall, the findings from this study revealed that drivers altered their acceleration behavior for executing risky driving decisions under increasing time pressure driving conditions.     

Using the picture exchange communication system (PECS) with children with autism: assessment of PECS acquisition,speech, social-communicative behavior,and problem behavior

The picture exchange communication system (PECS) is an augmentative communication system frequently used with children with autism (Bondy & Frost, 1994; Siegel, 2000; Yamall, 2000). Despite its common clinical use, no well-controlled empirical investigations have been conducted to test the effectiveness of PECS. Using a multiple baseline design, the present study examined the acquisition of PECS with 3 children with autism. In addition, the study examined the effects of PECS training on the emergence of speech in play and academic settings. Ancillary measures of social-communicative behaviors and problem behaviors were recorded. Results indicated that all 3 children met the learning criterion for PECS and showed concomitant increases in verbal speech. Ancillary gains were associated with increases in social-communicative behaviors and decreases in problem behaviors. The results are discussed in terms of the provision of empirical support for PECS as well as the concomitant positive side effects of its use.     

Effects of continuous and intermittent reinforcement for problem behavior during functional communication training

We evaluated the effectiveness of functional communication training (FCT) in reducing problem behavior and in strengthening alternative behavior when FCT was implemented without extinction. Following the completion of functional analyses in which social-positive reinforcement was identified as the maintaining variable for 5 participants' self-injurious behavior (SIB) and aggression, the participants were first exposed to FCT in which both problem behavior and alternative behavior were reinforced continuously (i.e., on fixed-ratio [FR] 1 schedules). During subsequent FCT conditions, the schedule of reinforcement for problem behavior was made more intermittent (e.g., FR 2, FR 3, FR 5, etc.), whereas alternative behavior was always reinforced according to an FR 1 schedule. Results showed that 1 participant's problem behavior decreased and alternative behavior increased during FCT when both behaviors were reinforced on FR 1 schedules. The remaining 4 participants shifted response allocation from problem to alternative behavior as the schedule of reinforcement for problem behavior became more intermittent. These results suggest that individuals might acquire alternative responses during FCT in spite of inconsistencies in the application of extinction, although even small errors in reinforcement may compromise treatment effects.     

Social stories, written text cues, and video feedback: effects on social communication of children with autism.

This study investigated the effects of written text and pictorial cuing with supplemental video feedback on the social communication of 5 students with autism and social deficits. Two peers without disabilities participated as social partners with each child with autism to form five triads. Treatment was implemented twice per week and consisted of 10 min of systematic instruction using visual stimuli, 10 min of social interaction, and 10 min of self‐evaluation using video feedback. Results showed increases in targeted social communication skills when the treatment was implemented. Some generalized treatment effects were observed across untrained social behaviors, and 1 participant generalized improvements within the classroom. In addition, naive judges reported perceived improvements in the quality of reciprocal interactions. These findings support recommendations for using visually cued instruction to guide the social language development of young children with autism as they interact with peers without disabilities.     

Trusting strangers: The benefits of reciprocal self-disclosure during online computer-mediated communication and mediating role of interpersonal liking

Reciprocal self-disclosure has reportedly been associated with increased interpersonal trust. However, existing research mainly focuses on online disclosure between acquaintances and overlooks the types of reciprocal disclosure, especially in the initial interactions between strangers communicating online. This study aimed to investigate how three types of reciprocal self-disclosure (turn-taking reciprocity, extended reciprocity and non-reciprocity) contribute to trust and the mechanism of positive interpersonal liking, and whether any effect was instant and stable or increased across two interactions during computer-mediated communication (CMC). Participants were assigned to one of the three reciprocal disclosure conditions and engaged in online interactions. Self-reported and behavioural results demonstrated higher levels of interpersonal trust and liking in the second interaction phase than in the first across all conditions. The turn-taking reciprocity condition showed higher interpersonal trust than did the extended condition, and higher interpersonal liking than did the extended and non-reciprocity conditions; this effect was apparent in both interactions. These findings help us understand the relationship between online self-disclosure and interpersonal trust, suggesting that certain patterns of communication with strangers (e.g., turn-taking reciprocity) may foster more positive social outcomes during CMC over time, while demonstrating the importance of immediacy in synchronous conversations.     

Police communication programmes aimed at burglary victims: A review of studies and an experimental evaluation

The effects and side-effects of a victim assistance project aimed at victims of burglary are experimentally evaluated. Key features of the programme included the provision of burglary prevention information by police officers during a personal interaction with the victim through a positive and limitative communication strategy. Results suggest that important programme goals (for example, stronger satisfaction with police performance, a more internal risk orientation concerning victimization, stronger preventive intentions) were met. One of the positive effects for which experimental support was found was an improvement in police-victim relations. As regards side-effects the programme led neither to response generalization, nor to increased fear of crime outside the home. However, the side-effects of increased fear in the home did occur in female victims and victims with an external risk-orientation. The implications for future victim assistance projects in this domain are finally discussed.