Street-crossing Behavior Research Articles

Safety analysis of pedestrians distracted by mobile phones at street crossings: Field study in Nanjing

The growing public concern over traffic safety hazards caused by pedestrians’ distracted behavior, particularly related to mobile phone usage at pedestrian crossings. Through video recording of pedestrians’ street-crossing behaviors on 12 sidewalks across 9 urban road intersections in Nanjing city, 1778 valid pedestrian samples were collected. The study categorizes mobile phone use during the crossing into five distinct types: no use, voice call, screen gaze, screen gaze with operation, and listening to music with headphones. Then, the effects of gender, age and companion conditions on the mobile phone during the crossing were examined by chi-square tests. Utilizing binomial logistic and Relogit regression models, the study analyzed the impact and safety risks of distraction on crossing behavior. Additionally, a random parameters (RP) logit model with heterogeneity in means was used to investigate the determinants affecting mobile phone usage. Notably, individuals aged 18 to 30 years were identified as the random parameter, while factors such as being under 18 years old, having a companion without interaction, having a companion with interaction, weekdays, sidewalk length, and the total number of other pedestrians were identified as fixed parameters. The study also presented significant variables affecting the probability of mobile phone usage through marginal effects, highlighting the potential safety risks associated with mobile phone usage during street crossing. These findings emphasize the need for heightened pedestrian safety awareness and a reduction in distracted behaviors to enhance overall traffic safety.

Developmental differences in children’s adaptation to vehicle distance and speed in street-crossing decision-making

Introduction: Young children cannot effectively adapt their behaviors to vehicles at varied distances and speeds, which is a critical cause of road accidents. However, the impact of this crucial ability on children’s street-crossing decision-making and the age at which they acquire it remain unclear. Method: This study examined the crossing decision-making behavior of children at 6, 8, and 11 years of age in facing 51 different videotaped traffic scenarios with varying vehicle distances and speeds. Sixty Chinese elementary school students, with 20 children evenly distributed into each of the three age groups (6 years, 8 years, and 11 years old), participated in a simulated street-crossing task using video projections. Hierarchical logistic regression models were used to analyze how age moderated the effects of vehicular motion factors (vehicle–pedestrian distance, vehicle speed) on children’s crossing safety, including dangerous crossing and crossing decision-making. Results: The results showed that when either vehicle–pedestrian distance decreased or vehicle speed increased all age groups tended to cross less frequently but probability of dangerous crossing increased. Compared to 8-year-old and 11-year-old children, 6-year-old children showed a less pronounced tendency toward both of these crossing decision-making behaviors, and had more dangerous crossing outcomes. Conclusions: These findings suggest that inadequate adaptation to vehicle–pedestrian distance and vehicle speed may partly contribute to the inferior safety of street-crossing behavior in 6-year-olds compared to 8-year-olds. No significant differences were observed between 8- and 11-year-old children, suggesting the turning point for this ability might occur between 6 and 8 years of age. Practical Applications: Preventive measures aimed to reduce crossing risks for children should consider children’s developmental stages.

Effects of smartwatch usage on Children’s street-crossing behavior and visual attention allocation: An experimental study on street crossing in a real road environment

The use of smartwatches is facilitating the lives of children. However, smartwatch usage while crossing a street may lead to distractions and traffic safety hazards. The purpose of this study was to investigate the effects of smartwatch usage on the street-crossing behavior and visual strategies of children. Twenty-two children were recruited, and 220 street-crossing experiments were performed in real road environments, including at signalized and unsignalized intersections. ANOVA and Kruskal–Wallis H test calibrations were used to analyze the street-crossing behavior between the control group (who performed a task without smartwatch distraction) and the experimental group (who performed four different tasks with smartwatch distraction), and to visualize and compare the visual behavior data of children crossing the street. The results showed that children wearing smartwatches crossed the street more slowly and had a relatively narrow range of visual search, focusing on only a small area of the zebra crossing around them and the crosswalk area within their sight, whereas children who did not wear smartwatches additionally focused on areas with dangerous oncoming traffic on the left and right sides. Children wearing smartwatches were under various mental workloads and distraction levels as they performed the various distracting tasks, with listening to stories being the least distracting and least intensive, followed by answering phone calls and viewing images; a simple arithmetic operation was the most distracting and intensive task. Children while performing the distracting tasks showed a lower street-crossing speed and scanned left and right fewer times; viewing images and performing the simple arithmetic task also increased their fixation time on the smartwatches, further affecting their street-crossing behavior and thus increasing the risk of collision. At signalized intersections, children paid more attention to hazardous oncoming traffic areas and exhibited cautious crossing behaviors compared with that at unsignalized intersections. This study elucidated the characteristics of the effects of smartwatch usage on the street-crossing behavior of children and the influence pattern of the visual attention allocation and revealed the hazards of smartwatch usage on the street-crossing safety. It can contribute to improving the safety cognition of children distracted by smartwatch usage and reducing the occurrence of distracting behaviors while crossing streets. The results can provide a theoretical basis for scientific interventions and safety improvement measures.

Bicycle safety outside the crosswalks: Investigating cyclists' risky street-crossing behavior and its relationship with built environment

Most bicycle accidents are inextricably bound up with risky riding behaviors, which crossing the street illegally at unprotected mid-block locations is nothing to sneeze at. Compared with cyclists crossing the street at the crosswalk or intersections, there is a huge risk of accidents when they ignore or disobey road rules and across recklessly. Yet, the misbehavior of cyclists is an under-explored area in cyclist research due to the limited availability of detailed cycling data. This study creatively develops a GPS-based detection framework to capture risky street-crossing actions for the cyclists from large-scale bike sharing trajectory data. A data-driven modeling approach, based on structural topic modeling (STM), is developed to reveal the complexity and regularity of cyclists' habitual risky crossing behavior. Since objective built environment is one of the key factors associated with cycling, another goal of this paper is to apply a gradient boosting decision tree (GBDT) model to disentangle how the features of built environment may influence the frequency of risky crossing events. The case study results show that risky street-crossing behavior is prevalent in bicycle traffic – for example, 16.94% of cycling trips are involved in illegal crossing action. Most cyclists engage in illegal crossing behavior at the approximate central part of the streets and during the day, which reveals the presence of heterogeneity over space and time. Strong correlations between commuting activities and risky street-crossing behaviors are identified from topic modeling. Meanwhile, the latent illegal crossing patterns unraveled here highlight that typical reasons for committing the risky riding action include the lure of the travel destination across the road and the inconvenience of riding round in distant legal crossing facilities. GBDT findings provide new insights on the existence of the association between built environment and cyclists' illegal crossing action. The places related employment and catering play a dominant role in contributing risky street-crossing behavior, and the influences of road length, road level, bus stop and metro station are not neglectable. Most built environment attributes show nonlinear correlations with crossing frequency. It is anticipated that this study would successfully shed a first light on the pattern of cyclists' risky street-crossing behavior at the metropolitan scale, and compliment engineering practices to improve crossing behaviors and bicycle safety.

How does attention deficit hyperactivity disorder affect children’s road-crossing? A case-control study

Objective: Children diagnosed with attention-deficit/hyperactivity disorder (ADHD) may have particularly high pedestrian injury risk given their deficits in attention, inhibition, and concentration. The aims of this study were a) to assess differences in pedestrian skill between children with ADHD and typically-developing children and b) to examine relations between pedestrian skill and attention, inhibition, and executive function among children with ADHD as well as among typically-developing children. Methods: A sample of 50 children with mean age of 9 years participated, 56% of them diagnosed with ADHD. Children completed IVA + Plus, an auditory-visual test evaluating impulse response control and attention and then engaged in a Mobile Virtual Reality (MVR) pedestrian task to assess pedestrian skills. Parents completed the Barkley’s Deficits in Executive Functions Scale-Child & Adolescents (BDEFS-CA) to rate children’s executive function. Children with ADHD engaged in the experiment off any ADHD medications. Results: Independent samples t-tests indicated significant differences between the two groups in all IVA + Plus and BDEFS_CA scores, supporting the clinical diagnoses of ADHD and the distinction between the two groups. Independent samples t-tests also indicated differences in pedestrian behavior: Children in the ADHD group had significantly higher numbers of unsafe crossings in the MVR environment. Partial correlations within samples stratified by ADHD status indicated that for both groups of children, there were positive correlations between unsafe pedestrian crossings and executive dysfunction. There were no relations between IVA + Plus attentional measures and unsafe pedestrian crossings in either group. A linear regression model predicting unsafe crossings was significant, with children with ADHD more likely to cross in a risky manner after controlling for executive dysfunction and child age. Conclusions: ADHD children exhibited riskier street-crossing behavior in the MVR, confirming an increased risk of pedestrian injury among children with ADHD compared to typically-developing children. Risky crossing among the typically-developing children and ADHD was related to deficits in executive function. Implications are discussed in relation to parenting and professional practice.

Evaluating the effectiveness of crosswalk tactile paving on street-crossing behavior: A field trial study for people with visual impairment

People with visual impairment cannot easily obtain external information through vision and thus they face more challenges when traveling than sighted people. The travel environment for people with visual impairment includes pedestrian safety concerns, especially when crossing roads at intersections. Tactile paving can be used as a guidance cue for street-crossing purposes but its use is not yet widespread globally (except at some test sites in Japan). This study investigated the effectiveness of tactile paving on crosswalks based on a field trial conducted in China. A drone and three-axis accelerometer were used to collect participants’ behavioral data. Several quantitative indices for street-crossing behavior, including trajectory, maximum distance of the directional deviation, crossing speed, crossing time, and gait regularity and symmetry, were investigated to measure the participants’ street-crossing performance. Before-after comparative analysis of the quantitative index results was conducted to compare the participants’ use of crosswalks with and without tactile paving. The results reveal that tactile paving helps people with visual impairment to maintain a straight crossing path, avoid directional deviation, reduce their crossing time, and improve their gait regularity and symmetry. Study participants reported positive impressions of the effectiveness of crosswalk tactile paving based on one-to-one interviews conducted after the crosswalk tests. The results also indicate that crosswalk tactile paving is more effective for people with blindness than for those with low vision. This study’s findings could serve as a theoretical basis for the deployment of various barrier-free traffic facilities (especially street-crossing facilities) for people with visual impairment.

Is the street-crossing behavior with a head-mounted display different from that behavior in a CAVE? A study among young adults and children

The use of virtual reality (VR) has become increasingly popular in the field of traffic psychology, where realistic traffic situations can be simulated and pedestrians‘ actual crossing behavior can be studied. There are two main kinds of pedestrian simulators: one uses a technology based on rear-projection screens (Cave Automatic Virtual Environment, or CAVE); the other uses a head-mounted display (HMD). Despite their extensive use, it is yet to determine whether they are equally suitable for studying street crossing. The present study was aimed at comparing street-crossing behavior and subjective evaluations in an HMD-based (HTC vive pro) pedestrian simulator and a CAVE-like pedestrian simulator, among young adults and 12-year-old children. Thirty young adults and twenty-six children performed 36 street-crossing trials (combining different speeds, traffic conditions, and gap sizes) on each of the two simulators. The results indicated that, compared to the CAVE-condition participants, HMD-condition participants accepted more crossing trials (hence, shorter gaps), initiated their crossings sooner, crossed at a slower speed, had shorter safety margins, and caused more collisions. The main difference between the two devices was in crossing initiation, which occurred markedly earlier (1.72 s) with the HMD than in the CAVE: the perception–action coupling was less finely tuned in the CAVE, probably because visual information in front of the pedestrian was missing due the absence of ground projection and 3D rendering. A significant effect of vehicle-approach speed was observed for both devices, with more unsafe behaviors at 60 km/h than at 40 km/h. Children displayed riskier crossing behavior than young adults did, with more accepted crossings, slower crossing speeds, shorter safety margins, and higher collision rates, especially in the HMD. Compared to the CAVE, the HMD received higher ratings for level of presence and a preference for VR, but also higher simulator-sickness scores. No adverse effects of exposure to virtual reality was found on stereoacuity or postural balance. The suitability of using CAVE and HMD simulators is discussed, especially for studying child pedestrians.

Analysis of Street-Crossing Behavior: Comparing a CAVE Simulator and a Head-Mounted Display among Younger and Older Adults

Interactive pedestrian simulators have become a valuable research tool for investigating street-crossing behavior and developing solutions for improving pedestrian safety. There are two main kinds of pedestrian simulators: one uses a technology based on rear-projection screens (Cave Automatic Virtual Environment, or CAVE), the other a head-mounted display (HMD). These devices are used indiscriminately, regardless of the research objective, and it is not yet known whether they are equally effective for studying street crossing. The present study was aimed at comparing the street crossing behavior and subjective evaluations of younger and older adult pedestrians when they are using a CAVE-like or HMD-based (HTC Vive Pro) pedestrian simulator. Thirty younger adults and 25 older adults performed 36 street-crossing trials (combining different speeds, two-way traffic conditions, and gap sizes) on each of the two types of simulators. The results indicated that participants in the HMD condition crossed the street significantly more often (58.6 %) than in the CAVE condition (42.44%) and had shorter safety margins. The most striking difference pertained to crossing initiation, which occurred considerably earlier (1.78 s) in the HMD condition than in the CAVE condition. Synchronization of crossing initiation with oncoming traffic was not as good in the CAVE condition because visual information in front of the pedestrian was missing due to the absence of ground projection. In both simulators, older adults caused more collisions than did younger ones, had shorter safety margins, and a slower crossing speed. Hence, the HMD reproduced classical age-related differences in most street-crossing behaviors already found on the CAVE. Usually observed speed effects were also found for both simulators. Neither cybersickness nor any adverse effects on stereoacuity or postural balance were found for either simulator. The HMD produced a higher level of presence and preference than the CAVE did. These findings provide evidence that HMDs have a clear potential for studying pedestrian behaviour.

Understanding Sex Differences in Children’s Injury Risk as Pedestrians

Boys experience more injuries as pedestrians than girls. The aim of this study was to compare how boys and girls cross streets in order to identify factors that differentially influence their injury risk as pedestrians. Using a fully immersive virtual reality (VR) system interfaced with a 3D movement measurement system, various measures of children's street-crossing behaviors were taken. At the start of the crossing, boys selected smaller (riskier) inter-vehicle gaps to cross into than girls. Subsequently, as they crossed, they showed greater attention to traffic, shorter start delay, and more evasive action than girls, which are strategies that could reduce risk as a pedestrian. Despite these efforts, however, boys experienced more hits and close calls than girls. To enhance their safety as pedestrians, girls adopt a proactive approach and select larger inter-vehicle gaps to cross into, whereas boys apply a reactive approach aimed at managing the risk created by having selected smaller (riskier) gaps. Girls' proactive approach yielded safer outcomes than boys' reactive strategy.

Interactive Education is Associated With Lower Incidence of Pedestrian-Related Injury in Children

BackgroundPedestrian-related injuries are a significant contributor to preventable mortality and disability in children. We hypothesized that interactive pedestrian safety education is associated with increased knowledge, safe crosswalk behaviors, and lower incidence of pedestrian-related injuries in elementary school-aged children. MethodsAn interactive street-crossing simulation was implemented at target elementary schools in Los Angeles County beginning in 2009. Mixed-methods were used to evaluate the impact of this intervention. Multiple-choice examinations were used to test pedestrian safety knowledge, anonymous observations were used to assess street-crossing behaviors, and statewide traffic records were used to report pedestrian injuries in elementary school–aged (4-11 y) children in participating school districts. Pedestrian injury incidence was compared 1 y before and after the intervention, standardized to the incidence in the entire City of Los Angeles. ResultsA total of 1424 and 1522 children completed the pretest and post-test, respectively. Correct answers increased for nine of ten questions (all P < 0.01). Children more frequently looked both ways before crossing the street after the intervention (10% versus 41%, P < 0.001). There were 6 reported pedestrian-related injuries in intervention school districts in the year before the intervention and 2 injuries in the year after the intervention, resulting in a significantly lower injury incidence (standardized rate ratio 0.28; 95% CI, 0.11-0.73). ConclusionPedestrian safety education at Los Angeles elementary schools was associated with increased knowledge, safe street-crossing behavior, and lower incidence of pediatric pedestrian–related injury. Formal pedestrian safety education should be considered with injury prevention efforts in similar urban communities.

Effects of Peers on Child Pedestrian Behaviors in a Virtual Traffic Context

Research shows that school-aged children are at high risk of pedestrian injury when they cross streets with peers. How peers exert their influence is unknown. Using a fully immersive virtual reality pedestrian environment, this study examined the impact of peers on children's pedestrian behaviors. 137 children were assigned either to a control, peer observer, or peer-safety or peer-risky modeling condition. Street-crossing behaviors were measured twice (baseline, postbaseline), with group comparisons (control vs. test condition) of postbaseline scores conducted. Children who observed a peer modeling risky behaviors imitated this. No significant influences were found in the peer observation or safe modeling conditions. Peers may elevate other children's risk of pedestrian injury through modeling risky crossings. Implications for prevention are discussed.

Traffic safety education for child pedestrians: A randomized controlled trial with active learning approach to develop street-crossing behaviors

Child Pedestrians are among the most-at-risk populations for road traffic injuries. Our aim in the present study was to investigate the effectiveness of an active learning-based educational intervention on street-crossing behaviors of seven-year-old children. In this randomized controlled trial, 149 first-grade students were selected from two male elementary schools in Mehriz City, Iran, to participate in the study. The participants were randomly assigned into two experimental groups (n = 103, Active-Learning based training group [A.L] (n = 52) and Active-Learning based training with Parental Involvement group [P.I & A.L] (n = 51) and a control group (n = 46, without training group). The instructional program was based on active learning theory and parental involvement approach. Street-crossing behaviors of the students were assessed in an actual traffic environment in three phases: before training, one week after training, and six months after training. The behaviors of students in the experimental groups were significantly improved within one week, and later the six month time frames. Their performance was linearly improved by time (looking for vehicles on the street: F = 3.35P < 0.01; crossing from safe places: F = 10.5, P < 0.0001). No behavioral difference was found among the students in the control group. After six months, there was a better improvement (P = 0.0001) in the street-crossing behaviors of children in the P.I & A.L groups, compared to the A.L group. Our results confirmed the positive effects of active learning-based education with parental involvement approach on improving the street-crossing behaviors of 7-year-old children. Parental involvement is recommended as a useful strategy while designing active learning-based educational programs aiming at the improvement of street-crossing behaviors among school-aged children.

Improving safe street-crossing behaviors among primary school students: a randomized controlled trial.

Background: Child pedestrian injury is a global public health concern. Our aim in the present study was to investigate the effects of active learning-based educational intervention on street-crossing behavior among male primary school students in Mehriz county, Iran.Methods: In this randomized controlled trial, 90 first grade elementary school students(experiment = 50, control group = 48) participated. The "ASSURE Model" was applied to design the template of this active learning-based educational program, which was implemented for the experiment group in eight sessions. Behaviors of the students about ‘’looking for vehicles on the street’’, "being cautious of dangers’’ and ‘’crossing from safe places’’ were observed and documented in actual traffic environments before, 1 week, and 6 months after intervention.Results: One week and 6 months after the intervention, the experiment group’s performance in all 3 behaviors were significantly improved (P < 0.001). Distraction-adjusted differences in the mean scores of behaviors between the experiment (Mean = 2.62) and control (Mean = 3.19)groups before and 6 months after intervention (Mean in experiment groups = 6.3, Mean in control group = 4.24) were also statistically significant (P < 0.001).Conclusion: Our educational intervention was found to be helpful in promoting the street crossing behaviors of primary school-aged children. School healthcare professionals may apply active learning education as the core category of their interventional programs to promote street-crossing behaviors among primary school students.

Identifying association between pedestrian safety interventions and street-crossing behavior considering demographics and traffic context

Pedestrian fatalities are becoming a larger percentage of overall fatalities in the United States, therefore better understanding of the expected effects of any interventions/treatments aimed at modifying pedestrian behavior is essential for improving safety. This study used pedestrian safety interventions to assess their effect on respondents’ stated crossing behavior. Also, specific demographic data was used to identify behavioral trends regarding street-crossing behavior. Results show that safety interventions are significantly associated with changes in crossing behavior. The effect of interventions was predominantly positive, because the respondents’ behavior after the interventions showed improvement relative to comparison group. This study found significant association between demographic variables and the compliance rate. Women were more compliant than men, and respondents age 25 or younger were more compliant after the interventions. Married respondents were more compliant than unmarried ones. Respondents who drive often were more compliant, but having been involved in a car accident as a pedestrian (or knowing someone who was) was not significant in explaining crossing behavior. The findings from this study could serve as a guide of potential factors/variables to be taken into consideration when studying street-crossing behavior and consequently could help to improve pedestrian street-crossing behavior models.

Child Pedestrian Street-Crossing Behaviors outside a Primary School: Developing Observational Methodologies and Data from a Case Study in Changsha, China.

Child pedestrian injury is a significant global public health challenge, and prevention programming requires an understanding of the context children face when crossing the street. Methods to understand children's behavior in real-world pedestrian settings are sparse in low- and middle-income countries. Children in grades 1-6 were videotaped crossing a three-lane street outside their school in Changsha, China. Tapes were coded to collect: (1) extent of adult supervision, (2) whom children crossed the street with, and (3) safe behaviors exhibited by children. Observational videotape methods yielded data that could be reliably coded to understand Chinese children's behavior crossing the street outside their primary school. In total, we observed 216 child pedestrians crossing the street, including 105 girls, 105 boys, and 6 for whom gender could not be determined. 51% of observations occurred in the morning before school and 49% in the afternoon after school. Children encountered a busy and somewhat-chaotic traffic environment. Adults were always present to help, but children appeared to heed adult advice concerning the crossing only about 70% of the time. Fewer than 1/3 of children looked at oncoming traffic before they entered a lane and over 1/3 entered a lane with moving traffic approaching. Observational methods of coding videotaped behavior proved effective to understand and code children's risk and safety while crossing the street outside their primary school. At the street environment we studied, we found that children's pedestrian behavior involved significant risk.

Smartphone gaming is associated with pedestrians' head-turning performances: An observational study of street-crossing behaviors at uncontrolled intersection in Taipei

ABSTRACTPedestrians' head-turning behaviors are crucial to navigating streets safely. This research investigates the effects of phone use on pedestrians' street-crossing behaviors at an uncontrolled intersection where head-turning performances are important to identify a gap among the oncoming traffic. A field study using video cameras was conducted for evaluating pedestrians' head-turning behaviors (e.g., head-turning frequency, not looking at traffic before crossing, looking at the wrong traffic side), crossing time, and sudden movement while they were engaging in various smartphone activities (e.g., calling, texting, gaming, and listening to music). Data such as phone features, distraction types, and personal attributes of the pedestrians were obtained in the interviews conducted after pedestrians had completed crossing the street. The results indicate that the unsafe crossing behaviors (e.g., sudden movement, fewer head-turning frequencies, not looking at traffic before crossing, not looking at left side of traffic first) were more prevalent among those gaming with “Pokemon Go.” Web surfing appears to be the 2nd risky distraction event following gaming with “Pokemon Go.” Logistic regression models reveal several important correlates of unsafe crossing behaviors: being a student, large phone screen (5 in. or larger), and having un-restricted 4G Internet data allowance. The current research recommends that “Pokemon Go” gaming be prohibited while crossing the street.

The impact of walking while using a smartphone on pedestrians’ awareness of roadside events

Previous studies have shown that using a cell phone to talk or text while walking changes gait kinematics and encourages risky street-crossing behaviors. However, less is known about how the motor-cognitive interference imposed by smartphone tasks affects pedestrians’ situational awareness to environmental targets relevant to pedestrian safety. This study systematically investigated the influence of smartphone use on detection of and responses to a variety of roadside events in a semi-virtual walking environment. Twenty-four healthy participants completed six treadmill walking sessions while engaged in a concurrent picture-dragging, texting, or news-reading task. During distracted walking, they were required to simultaneously monitor the occurrence of road events for two different levels of event frequency. Performance measures for smartphone tasks and event responses, eye movements, and perceived workload and situational awareness were compared across different dual-task conditions. The results revealed that during dual-task walking, the reading app was associated with a significantly higher level of perceived workload, and impaired awareness of the surrounding environment to a greater extent compared with the texting or picture-dragging apps. Pedestrians took longer to visually detect the roadside events in the reading and texting conditions than in the dragging condition. Differences in event response performances were mainly dependent on their salient features but were also affected by the type of smartphone task. Texting was found to make participants more reliant on their central vision to detect road events. Moreover, different gaze-scanning patterns were adopted by participants to better protect dual-task performance in response to the changes in road-event frequency. The findings of relationships between workload, dual-task performances, and allocation strategies for visual attention further our understanding of pedestrian behavior and safety. By knowing how attentional and motor demands involved in different smartphone tasks affect pedestrians’ awareness to critical roadside events, effective awareness campaigns might be devised to discourage smartphone use while walking.

Virtual street-crossing performance in persons with multiple sclerosis: Feasibility and task performance characteristics

ABSTRACTObjectives: Multiple sclerosis (MS) is a neurological disease that commonly results in physical and cognitive dysfunction. Accordingly, MS might impact the ability to safely cross the street. The purpose of this study was to examine the feasibility of a simulated street-crossing task in persons with MS and to determine differences in street-crossing performance between persons with MS and non-MS controls.Methods: 26 participants with MS (median Expanded Disability Status Scale [EDSS] score = 3.5) and 19 controls completed 40 trials of a virtual street-crossing task. There were 2 crossing conditions (i.e., no distraction and phone conversation), and participants performed 20 trials per condition. Participants were instructed that the goal of the task was to cross the street successfully (i.e., without being hit be a vehicle). The primary outcome was task feasibility, assessed as completion and adverse events. Secondary outcomes were measures of street-crossing performance.Results: Overall, the simulated street-crossing task was feasible (i.e., 90% completion, no adverse events) in participants with MS. Participants with MS waited longer and were less attentive to traffic before entering the street compared with controls (all P < .05). Participants with MS also took longer to cross the street and were closer to oncoming vehicles when exiting the street compared to controls (all P < .05). When distracted, all participants took longer to initiate crossing, took longer to cross the street, and made more head turns while crossing (all P < .05). There were no significant group by condition interaction effects (all P > .05).Conclusions: A virtual street-crossing task is feasible for studying street-crossing behavior in persons with mild MS and most individuals with moderate MS. Virtual street-crossing performance is impaired in persons with MS compared to controls; however, persons with MS do not appear to be more vulnerable to a distracting condition. The virtual reality environment presents a safe and useful setting for understanding pedestrian behavior in persons with MS.

The Impact of a Signalized Crosswalk on Traffic Speed and Street-Crossing Behaviors of Residents in an Underserved Neighborhood.

Infrastructure improvements such as pedestrian crosswalks that calm traffic and increase access to physical activity opportunities could alleviate important barriers to active living in underserved communities with outdated built environments. The purpose of this study was to explore how the built environment influences street-crossing behaviors and traffic speeds in a low-income neighborhood with barriers to active living in Columbia, Missouri. In 2013, a signalized pedestrian crosswalk and 400-ft-long median was constructed along a busy 5-lane, high-speed arterial highway linking low-income housing with a park and downtown areas. Data collection occurred prior to June 2012, and after June 2013, completion of the project at the intervention site and control site. Direct observation of street-crossing behaviors was performed at designated intersections/crosswalks or non-designated crossing points. Traffic volume and speed were captured using embedded magnetic traffic detectors. At the intervention site, designated crossings increased at the new crosswalk (p < 0.001), but not at non-designated crossings (p = 0.52) or designated crossings at intersections (p = 0.41). At the control site, there was no change in designated crossings (p = 0.94) or non-designated crossings (p = 0.79). Motor vehicles traveling above the speed limit of 35 mph decreased from 62,056 (46 %) to 46,256 (35 %) (p < 0.001) at the intervention site and increased from 57,891 (49 %) to 65,725 (59 %) (p < 0.001) at the control site. The installation of a signalized crosswalk facilitated an increase in safe street crossings and calmed traffic volume and speed in an underserved neighborhood. We believe these findings have significant public health implications that could be critical to advocacy efforts to improve infrastructure projects in similar communities.

An accelerated failure time model for investigating pedestrian crossing behavior and waiting times at signalized intersections

The waiting process is crucial to pedestrians in the street-crossing behavior. Once pedestrians terminate their waiting behavior during the red light period, they would cross against the red light and put themselves in danger. A joint hazard-based duration model is developed to investigate the effect of various covariates on pedestrian crossing behavior and to estimate pedestrian waiting times at signalized intersections. A total of 1181 pedestrians approaching the intersections during red light periods were observed in Beijing, China. Pedestrian crossing behaviors are classified into immediate crossing behavior and waiting behavior. The probability and effect of various covariates for pedestrians’ immediate crossing behavior are identified by a logit model. Four accelerated failure time duration models based on the exponential, Weibull, lognormal and log-logistic distributions are proposed to examine the significant risk factors affecting duration times for pedestrians’ waiting behavior. A joint duration model is developed to estimate pedestrian waiting times. Moreover, unobserved heterogeneity is considered in the proposed model. The results indicate that the Weibull AFT model with shared frailty is appropriate for modelling pedestrian waiting durations. Failure to account for heterogeneity would significantly underestimate the effects of covariates on waiting duration times. The proposed model provides a better understanding of pedestrian crossing behavior and more accurate estimation of pedestrian waiting times. It may be applicable in traffic system analysis in developing countries with high flow of mixed traffic.