A comparative study of safe and unsafe signalized intersections from the view point of pedestrian behavior and perception

Signalized intersections with marked crosswalks enhance pedestrian safety by providing the designated right of way to pedestrians. However, a significant number of pedestrian fatalities occur at signalized intersections, which may primarily be due to pedestrians' violation behaviors. Since pedestrians' fatalities are not uniform across signalized intersections in a city, it may be expected that violations would also vary across the sites. It is thus worthwhile to investigate if the pedestrian signal violation is a good surrogate for fatal pedestrian crashes at signalized intersections, and if so, what behavioral, spatial, and built environment related factors influence such violations. To this end, present study analyzes pedestrian behavior and perceptions across twenty-four signalized intersections in Kolkata city, India, out of which twelve intersections did not record any fatal pedestrian crashes between 2011 and 2016 and the remaining twelve experienced at least three or more fatal pedestrian crashes over the same period. Using data from the video-graphic survey at these twenty-four signalized intersections violation behaviors are extracted along with personal attributes at the pedestrian level. Further, pedestrian perception surveys are carried out at each of the twenty-four sites, to obtain a user's perception of safety and satisfaction. Results indicate that pedestrians' signal violations behavior and dissatisfaction are statistically significantly higher at locations with recorded fatal pedestrian crashes. Results from different models and analysis clearly pointed out several planning and design deficiencies such as longer waiting time before crossing, higher pedestrian-vehicular interaction, pedestrian's state of crossing, and a number of personal level attributes such as pedestrian's intended mode of transportation and their state of journey, pedestrian's home location, pedestrian's socio-demographic characteristics as important predictors of pedestrians' violation behavior. The methodology and findings are useful not only for proactive safety improvement at signalized intersections but also to proactively identify potential unsafe sites.

Vulnerable road users in low-, middle-, and high-income countries: Validation of a Pedestrian Behaviour Questionnaire

The primary aim of this study was to validate the short version of a Pedestrian Behaviour Questionnaire across six culturally and economically distinct countries; Bangladesh, China, Kenya, Thailand, the UK, and Vietnam. The questionnaire comprised 20 items that asked respondents to rate the extent to which they perform certain types of pedestrian behaviours, with each behaviour belonging to one of five categories identified in previous literature; violations, errors, lapses, aggressive behaviours, and positive behaviours. The sample consisted of 3423 respondents across the six countries. Confirmatory factor analysis was used to assess the fit of the data to the five-factor structure, and a four-factor structure in which violations and errors were combined into one factor (seen elsewhere in the literature). For some items, factor loadings were unacceptably low, internal reliability was low for two of the sub-scales, and model fit indices were generally unacceptable for both models. As such, only the violations, lapses, and aggressions sub-scales were retained (those with acceptable reliability and factor loadings), and the three-factor model tested. Although results suggest that the violations sub-scale may need additional attention, the three-factor solution showed the best fit to the data. The resulting 12-item scale is discussed with regards to country differences, and with respect to its utility as a research tool in cross-cultural studies of road user behaviour.

Pedestrian overpass use and its relationships with digital and social distractions, and overpass characteristics

Pedestrian deaths and injuries are a major health issue in both developed and developing countries. In Vietnam, pedestrians account for about 10-11% of all road traffic deaths, while their travel distance contributes to approximately 2.4% of the total distance travelled by all modes. This paper aims to explore the use of pedestrian overpasses and identify influencing factors, particularly with regards to social and digital distractions, and overpass characteristics. An observational survey was conducted in Hanoi, Vietnam, in March 2017 at ten pedestrian overpasses. Behaviours of 608 pedestrians, including those who used an overpass to cross and those who illegally crossed, were observed. The rates of overpass usage varied significantly, between 35.9% and 96.5%. Modelling results suggest that pedestrians tended to compensate for the risks of illegal crossing by forming group and avoiding digital and social distractions (i.e., calling, operating a mobile phone's screen, listening to music, or talking to other pedestrians while crossing). In addition, overpass usage decreased with taller overpasses, but increased with wider overpasses. Effects of gender, weather, and illegal crossing speed on overpass use were also discussed.

Simulation of pedestrian evacuation route choice using social force model in large-scale public space: Comparison of five evacuation strategies

The primary objective of this study is to compare pedestrian evacuation strategies in the large-scale public space (LPS) using microscopic model. Data were collected by video recording from Tian-yi square for 36 hours in city of Ningbo, China. A pedestrian evacuation simulation model was developed based on the social force model (SFM). The simulation model parameters, such as reaction time, elasticity coefficient, sliding coefficient, et al, were calibrated using the real data extracted from the video. Five evacuation strategies, strategy 1 (S1) to strategy 5 (S5) involving distance, density and capacity factors were simulated and compared by indicators of evacuation time and channel utilization rate, as well as the evacuation efficiency. The simulation model parameters calibration results showed that a) the pedestrians walking speed is 1.0 ~ 1.5m/s; b) the pedestrians walking diameter is 0.3 ~ 0.4m; c) the frequency of pedestrian arrival and departure followed multi-normal distribution. The simulation results showed that, (a) in terms of total evacuation time, the performance of S4 and S5 which considering the capacity and density factors were best in all evacuation scenarios, the performance of S3 which only considering the density factor was the worst, relatively, and S1 and S2 which considering the distance factor were in the middle. (b) the utilization rate of channels under S5 strategy was better than other strategies, which performs best in the balance of evacuation. S3 strategy was the worst, and S1, S2 and S4 were in the middle. (c) in terms of the evacuation efficiency, when the number of evacuees is within 2, 500 peds, the S1 and S2 strategy which considering the distance factor have best evacuation efficiency than other strategies. And when the number of evacuees is above 2, 500 peds, the S4 and S5 strategy which considering the capacity factor are better than others.

Measurement properties of self-report pedestrians' road crossing behavior questionnaires constructed based on the theory of planned behavior: protocol for a systematic review

BACKGROUND

Pedestrians' unsafe crossing behavior exposes them at risk of trauma and death and puts a tremendous burden on the health care system. The theory of planned behavior (TPB) is one of the leading theoretical models used to develop pedestrians' road crossing behavior questionnaires, yet the quality of measurement properties of them has not been evaluated. The aim of the proposed systematic review is to evaluate the quality of measurement properties of the questionnaires constructed based on the TPB to predict pedestrians' road crossing behavior.

METHODS

We will include studies validating or evaluating one or more psychometric properties of the self-reported questionnaire employing the TPB for predicting pedestrians' road crossing behavior. A comprehensive search strategy will be formulated based on the components of review aim. The databases of MEDLINE, Embase, PubMed, Cochrane Library, PsycINFO, PsycARTICLES, and ProQuest, also grey literature and the reference lists of the included studies, will be searched. A hand search for the relevant journals and Google Scholar will be conducted. COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) Risk of Bias checklist will be used to evaluate the measurement properties of the included questionnaires. First, we will assess standards for the methodological quality of each study. Then, each scale or subscale of a questionnaire will be rated using the updated criteria for good measurement property. We will quantitatively pool or qualitatively summarize the results and will evaluate them against the criteria for good measurement properties. Finally, we will grade the pooled or summarized evidence using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach and provide recommendations for the most appropriate instrument.

DISCUSSION

The proposed systematic review will evaluate the measurement properties of self-report pedestrians' road crossing behavior questionnaires constructed based on the TPB. The findings will help researchers in selecting the appropriate TPB-based instrument for pedestrians' road crossing behavior.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42017047793.

Gap acceptance probability model for pedestrians at unsignalized mid-block crosswalks based on logistic regression

Gap acceptance represents a pedestrian's assessment of how safe it may be to use an available gap in traffic flow at a particular point in time. Though walking is a major component of urban mobility, the high rate of fatal interaction with motor vehicle traffic raises safety issues around how pedestrians decide to accept the available gap. This paper explored these interactions by modeling gap acceptance behavior at the midblock crosswalks. Unlike other pedestrian gap acceptance studies that focus on individual psychological and sociological factors that are difficult to control or manage, this study focused on six environmental factors that we considered important and as having the potential to affect the pedestrians' gap acceptance decision at the crosswalks, i.e. gap size, crossing distance, number of waiting pedestrians, waiting time, vehicle traffic volume and position of pedestrian (whether on street kerb or median). Video data was collected on pedestrian gap acceptance from 13 midblock crosswalk locations in Shanghai, China. A Logit model with 96% accuracy was developed to describe and predict the pedestrian gap acceptance behaviors. The results show that gap size and crossing distance have the highest effect on the pedestrian gap acceptance decision. Pedestrians waiting at the kerbside could confidently accept gaps (with a 95% probability) when the gap is longer than 2.2s, 5.9s, and 9.6s under the condition that the crossing distance is 4 m (one lane), 7.5 m (two lanes), and 11 m (three lanes), respectively while pedestrians waiting at the median could confidently accept gaps when the gap is longer than 1.6s, 5.3s, and 8.5s respectively under the same conditions. The recommendations on improving the crossing safety are proposed accordingly.

Assessing right-turning vehicle-pedestrian conflicts at intersections using an integrated microscopic simulation model

Frequent vehicle-pedestrian conflicts deserve special attention for safety assessment at intersections. This study helps verify how the simulation as an innovative approach can be utilized for right-turning vehicle-pedestrian conflict assessment at intersection crosswalks prior to implementation. Various behavior models such as vehicle turning path, turning speed, gap acceptance model and pedestrian behavior model, have been established. Through integrating the calibrated models into one simulation platform, the stochastic behavior of vehicles and pedestrians under different geometric layouts and operational conditions can be reproduced. Based on the field data collected by an unmanned aerial vehicle (UAV) at two urban intersections in Beijing, China, it was demonstrated through validation of surrogate safety measures (SSMs), i.e., Post Encroachment Time (PET) and vehicle passing speed at conflict points, that the simulation model can reasonably represent the frequency and severity of conflict occurrence at signalized crosswalks. The sensitivity analysis results indicated that large dimensions and turning angles of intersections tend to result in undesirable safety performance.

Behaviors of older pedestrians at crosswalks in South Korea

This paper aims to explore three walking behaviors of older pedestrians that may increase their crash risks when crossing urban streets. Older and younger pedestrians' start-up delay in initiating a crossing and number of head turns during street crossing are observed at 30 pedestrian crossings in Seoul, South Korea, using video recorders. In addition, their estimation of the safe crossing distance to an approaching vehicle is collected in a survey. Our study shows that older pedestrians have a shorter start-up delay time than younger pedestrians, older pedestrians crossing streets turn their heads less frequently, and older pedestrians provide less reliable estimates about the distance of an approaching vehicle. Safety technologies, campaigns and environmental designs should target these behaviors to improve the safety of older pedestrians.

Mobile device use while crossing the street: Utilizing the theory of planned behavior

Every year, thousands of pedestrians are killed and tens-of-thousands are nonfatally injured as a result of traffic crashes. The year 2016 holds the record for the most pedestrians killed in one year since 1990. Mobile device use while crossing the street has been associated with unsafe crossing behaviors and gait abnormalities, potentially increasing the risk of pedestrian injury or death. Expanding upon the small body of literature, the present study utilized the theory of planned behavior to guide the development of a questionnaire used to collect data from 480 adults on predictors of intentions to use a mobile device while crossing the street. Questionnaire development involved one round of expert panel review (N = 4), subsequent pilot testing of a revised questionnaire, and a test-retest reliability assessment. Results demonstrate that attitude toward the behavior, subjective norm, and perceived behavioral control significantly predicted the intention to use a mobile device while crossing the street in this population. Such a questionnaire can be used in the design and evaluation of TPB-based interventions to decrease distracted mobile device use while crossing the street.

Road risk behaviors: Pedestrian experiences

Objective: The objective of this study was to identify pedestrian risk behaviors that result in traffic accidents and characterization of the accidents experienced by participants in this study to provide information for the generation of integral preventive strategies. Methods: The study was correlational, descriptive, and transversal and followed a quantitative approach divided into 2 stages. In the first stage, an observational study was performed to identify the manifested risk behaviors of pedestrians, which served as a basis for the construction and design of a questionnaire. In the second stage, the questionnaire was applied to a group of 1,536 participants. Pearson's correlation coefficient was applied to establish associations between gender and age with respect to risk behaviors. Results: The 3 behaviors that participants reported performing always or very often include using electronic gadgets (except mobile phones), not using a pedestrian crosswalk, and using a mobile phone. In addition, 18.5% were involved in at least one road accident as a pedestrian in the last 5 years. Of the total number of registered accidents, 21% resulted in pedestrian injuries, 48.3% of which were serious. These were due to external causes not related to human factors or unidentified (58.5%) and behavior factors as a whole (41.4%, 31.5% of which were caused by pedestrians). Pearson's correlation coefficient showed evidence of a correlation between age and risk behaviors. Conclusions: All subjects in this study performed several risky actions as pedestrians, at least occasionally, and at least one fifth had been involved in a road accident as a pedestrian. It is known that the surroundings can positively or negatively influence individuals' behaviors; therefore, once prevention measures are identified, it is possible to influence risk behaviors. Therefore, road safety education and the physical environment must be considered together, and efforts focused on optimum infrastructure also need to consider road safety education.

Effect of positive airway pressure therapy in children with obstructive sleep apnea syndrome: does positive airway pressure use reduce pedestrian injury risk?

INTRODUCTION

Treatment with positive airway pressure (PAP) therapy reduces injury risk among adults with obstructive sleep apnea syndrome (OSAS), but the effect of PAP therapy on children's injury risk is unknown. This study investigated whether treatment of OSAS with PAP reduces children's pedestrian injury risk in a virtual reality pedestrian environment.

METHODS

Forty-two children ages 8-16 years with OSAS were enrolled upon diagnosis by polysomnography. Children crossed a simulated street several times upon enrollment, prior to PAP treatment, and again after 3 months of PAP therapy. Children underwent sleep studies at all time points.

RESULTS

Children adherent with PAP had a significant reduction in hits by a virtual vehicle (P < .01) and less time to contact with oncoming vehicles (P < .01) following treatment. Those who were nonadherent did not show improved safety. There was no change in attention to oncoming traffic.

CONCLUSIONS

OSAS may have significant consequences on children's daytime functioning in a critical domain of personal safety: pedestrian skills. In pedestrian simulation, children with OSAS adherent to PAP therapy showed improvement in pedestrian safety and had fewer collisions with a virtual vehicle following treatment. Results highlight need for heightened awareness of the real-world benefits of treatment for pediatric sleep disorders.

LEVEL OF EVIDENCE

Level II Therapeutic Study.

Pedestrian's risk-based negotiation model for self-driving vehicles to get the right of way

Negotiations among drivers and pedestrians are common on roads, but it is still challenging for a self-driving vehicle to negotiate for its right of way with other human road users, especially pedestrians. Currently, the self-driving vehicles are programmed for conservative behavior, yielding to approaching pedestrians. Consequently, the future urban traffic will slow down significantly. In this paper, a conceptual model of vehicle-pedestrian negotiation is proposed. This model allows individual decision making of multiple vehicles and pedestrians, extending a prior negotiation model for a single vehicle and a single pedestrian. The possible negotiation opportunities for vehicles are modeled considering different risk-taking behaviors of pedestrians. Simulation results show an overall improvement in the waiting time of vehicles and thus in the intersection throughput, compared to conservative vehicle behavior. The simulation results show also that the benefit of reduced waiting times for vehicles comes at the cost of some waiting time for pedestrians. However, the observed pedestrian waiting times in this model are not more than the generally accepted waiting times reported in empirical studies.

Shorten pedestrians' perceived waiting time: The effect of tempo and pitch in audible pedestrian signals at red phase

Long waiting time at red light leads to negative experiences and red-light running behaviors. To shorten pedestrians' experienced waiting time, this study explores how the tempo and pitch in audible pedestrian signals influence time estimation. In a simulated task of waiting at the red light, we compared pedestrians' estimation of waiting time for three durations (30 s, 45 s, 60 s) while the tempo (40 bpm, 60 bpm, 120 bpm, bpm as the number of beats per minute) and pitch (175 Hz, 350 Hz, 700 Hz) of the tone were manipulated. The results show that pedestrians' estimations of waiting time decreased with decreasing tempo in the audible signal, but did not differ significantly across different pitches. To verify the effect of tempo on time estimation in real crossing scenario, we interviewed 217 pedestrians randomly selected at six sites on their waiting time at different tempos. The tempo can still predict pedestrians' time estimation. The findings have implications for auditory signal design of traffic lights.

An experimental study to investigate design and assessment criteria: What is important for communication between pedestrians and automated vehicles?

In the near future, more vehicles will have automated functions. The traffic system will be a shared space of automated and manually driven vehicles. In our study we focused on the perspective of vulnerable road users, namely pedestrians, in cooperative situations with automated vehicles. Established communication methods, such as eye-contact between pedestrians and drivers, may no longer work when automated vehicles represent the interaction partner. Therefore, we evaluated several human-machine-interfaces (HMI) in order to implement smooth and comfortable communication. We conducted a two-stage study consisting of an explorative focus group discussion with naïve pedestrians (n = 6), followed by an experimental video simulation study (n = 25) based on the results of the focus group discussion. From the focus group we sought member opinion about various HMI, upon presentation of acoustic and visual communication systems such as projections, displays and LED light strips, in addition to portable communication systems, specifically smart watches. On the basis of the focus group discussion, an evaluation criteria was derived. For the video simulation study, HMI designs were created with variations in position, type and coding of the message, and technology. These were assessed by 25 subjects according to the focus discussion derived evaluation criteria: recognizability, unambiguousness, interaction comfort and intuitive comprehensibility. The results show that direct instructions to cross the street are preferred over status information of the vehicle and that large-scale text-based messages from the vehicle to the pedestrian, deliver better results. Design recommendations for HMIs for communication between automated vehicles are derived, and the extent external HMIs may supplement informal communication strategies such as vehicle movement or braking maneuvers, is discussed.

Evaluation of pedestrian crossing behavior and safety at uncontrolled mid-block crosswalks with different numbers of lanes in China

This study aims to investigate pedestrian crossing behavior and safety at uncontrolled mid-block crosswalks with different numbers of vehicle lanes. For this purpose, twelve uncontrolled mid-block crosswalks in Wuhan, China were selected to collect data via field investigation. Descriptive statistics were used to analyze pedestrian crossing behavior, and the distribution of pedestrian-vehicle conflicts on different vehicle lanes was given. Three ordered probit (OP) models for pedestrian-vehicle conflicts analysis (PVCA) were established to measure the effects of various factors on pedestrian safety. Descriptive statistical results showed that crosswalks with different numbers of lanes have diverse impacts on pedestrian crossing behavior and safety. As the number of vehicle lanes increases, the proportion of pedestrians adopting the rolling gap crossing mode, crossing the street with others, and changing the speed or path increase accordingly. Moreover, the number of pedestrian-vehicle conflicts at two-way six-lane crosswalks is 5.96 times higher than that of two-lane crosswalks, and 2.04 times higher than that of four-lane crosswalks. From the results of OP models, it was found that pedestrian behavioral characteristics such as rolling gap crossing mode, crossing with others significantly increased the possibility of pedestrian-vehicle conflicts.

Observing the observation of (vulnerable) road user behaviour and traffic safety: A scoping review

Behavioural observation studies in road safety research collect naturalistic data of road users that are not informed (beforehand) of their participation in a research project. It enables the observation of behavioural and situational processes that contribute to unsafe traffic events, while possible behavioural adaptations due to the road users' recognition of being observed are minimized. The literature in this field is vast and diverse, with studies dating back to the 1930s. The aim of this paper is to summarize the research efforts in the domain of road user behavioural observation research to examine trends and developments of this type of research, using a scoping review. After the definition of certain selection criteria, 600 journal articles found in three major online databases were retrieved and included in this review. The number of publications regarding road user behavioural observation studies has increased rapidly during recent years, indicating the importance of behavioural observation studies to study traffic safety. Most studies collected data on car drivers (81%), while vulnerable road users have been observed in 32% of all studies, with pedestrians and (motor)cyclists as the most common road user types. The results showed that the main goal of behavioural observation is to monitor (51%), followed by the evaluation of a specific safety improving measure (38%) and the development of behavioural models (10%). Most topics relate to traffic events where interactions with other road users are necessary, indicating that the examination of behavioural processes underlying single-vehicle crashes has received little attention. The ongoing developments of automated video analysis software tools can be the next methodological step forward in video-based behavioural observation studies, since it enables a more objective data collection and data analysis process.

Exploring patterns of child pedestrian behaviors at urban intersections

Children are more vulnerable as pedestrians due to their cognitive, physical and behavioral traits. However, walking is one of the main forms of travel for children, particularly during leisure hours. Child pedestrian injury primarily occurs in urban areas, with a significant share at crosswalks. This study observed child pedestrian behaviors at crosswalks of urban intersections aiming to characterize their behavior patterns and identify risk factors that may lead to injury. Crossing behaviors of children and adolescents up to age 18, during leisure hours, were video-recorded at 29 crosswalks, on signalized and un-signalized intersections situated on collector roads. Some children used pedestrian crosswalks while riding a bicycle or other non-motorized means; they were also included in the sample. Behaviors of 2930 young road users were encoded and compared by age groups. Multivariate logistic regression models were adjusted to identify factors associated with crossing on red and with non-checking vehicle traffic at un-signalized crosswalks. The findings pointed to different behavior patterns for the various child age groups. Risk-taking behaviors are higher for older children; adolescents aged 14-17 cross more on red, without checking traffic, outside crosswalk boundaries and while distracted. At all types of sites, a fifth of children over the age of 9 crossed by riding, the probability of crossing on red and of non-checking traffic prior to crossing at an un-signalized crosswalk was higher for children riding an electric bicycle or kick-scooter. The non-checking of traffic was also higher when a child is distracted by a mobile phone or other electronic gadget, or carries a big object. Children under age 9 were usually accompanied by adults but still exhibited risk-taking behaviors that apparently mirrored those of the adults. Risk-taking behaviors of young road users should be taken into account in the development of injury prevention programs focusing on child and parent education and training, and by adapting the urban environment to better meet their needs.

Simulating uni- and bi-directional pedestrian movement on stairs by considering specifications of personal space

This paper presents an enhanced model that considers the specifications of personal space to describe uni- and bi-directional pedestrian movement on stairs. The shape of the personal space of each pedestrian is regarded as an oval shape, which is composed of four arcs, to precisely quantify movements. Specific models that facilitate the simulation of movement include adjustments to individual speeds based on the proximity of other members, conflict avoidance, overtaking, and direction finding. By implementing these parameters in the simulation, basic data concerning these movement behaviours were collected from the experiment, which was carried out at one a Shanghai subway station. Twenty-four young college students participated in this experiment. Numerical simulation results for a stochastic case under those parameters were obtained. The fundamental diagrams and moving behaviours according to different proportions of ascending and descending pedestrians are analysed and discussed. The results indicate that the simulation platform for personal space can serve as a useful tool to evaluate pedestrian movement on stairs.

Gender differences in children's pedestrian behaviors: Developmental effects

INTRODUCTION

All child pedestrians are vulnerable to road traffic injuries, but there is evidence that boys may be at greater risk than girls, at least among some age groups.

METHOD

To create effective intervention programs, research on how boys and girls of particular ages behave as pedestrians, and whether there are gender differences that increase risk for particular genders at particular ages, is needed. In this study, 255 boys and 235 girls in grade 1 through 6 from two primary schools in Nantong city, China, were unobtrusively videotaped when walking to school in the morning. Videotapes were reviewed and coded for seven pedestrian safety behaviors, including activities related to crossing streets (walking instead of running/hopping, observing traffic, using the crosswalk instead of walking outside the crosswalk, and keeping close to an accompanying adult) and those related to walking alongside busy streets (walking instead of running/hopping on the sidewalk, not playing on the sidewalk, walking alone instead of walking side-by-side with a partner).

RESULTS

Results revealed that as a whole, boys played on the sidewalk more often than girls (p < 0.01) and crossed with an accompanying adult more than girls (p < 0.05), while girls walked side-by-side with partners more often than boys (p < 0.05). With a few exceptions, boys and girls in the younger grades (1-2) as well as those in the older grades (5-6) behaved fairly similarly as pedestrians, but boys and girls in the middle grades (3-4) presented with several significant gender-based differences. In the middle grades, boys watched traffic more than girls while crossing (p < 0.01); ran, hopped and played on the sidewalk more often than girls (p < 0.05); and walked side-by-side less often with partners than girls (p < 0.05). We also detected different gender-based trends in the development of pedestrian skills. With increasing age, girls performed more safely in pedestrian tasks, but boys did not show a similar developmental trend.

CONCLUSIONS

We conclude that boys and girls exhibit different characteristics in their pedestrian behaviors and discuss implications for prevention.

A System for Generating Customized Pleasant Pedestrian Routes Based on OpenStreetMap Data

In this work, we present a system that generates customized pedestrian routes entirely based on data from OpenStreetMap (OSM). The system enables users to define to what extent they would like the route to have green areas (e.g., parks, squares, trees), social places (e.g., cafes, restaurants, shops) and quieter streets (i.e., with less road traffic). We present how the greenness, sociability, and quietness factors are defined and extracted from OSM as well as how they are integrated into a routing cost function. We intrinsically evaluate customized routes from one-thousand trips, i.e., origin–destination pairs, and observe that these are, in general, as we intended—slightly longer but significantly more social, greener, and quieter than the respective shortest routes. Based on a survey taken by 156 individuals, we also evaluate the system’s usefulness, usability, controlability, and transparency. The majority of the survey participants agree that the system is useful and easy to use and that it gives them the feeling of being in control regarding the extraction of routes in accordance with their greenness, sociability, and quietness preferences. The survey also provides valuable insights into users requirements and wishes regarding a tool for interactively generating customized pedestrian routes.

The mediating effect of traffic safety climate between pedestrian inconvenience and pedestrian behavior

Because most people are pedestrians at some point on any given day and walking is the most indispensable means of transportation, pedestrian safety should be investigated. The primary aim of this study was to investigate the relationships among the inconveniences that pedestrians perceive in city traffic, the traffic safety climate and pedestrian behavior. A total of 311 participants voluntarily and validly completed a survey that included the Pedestrian Inconvenience Questionnaire (PIQ), the Traffic Climate Scale (TCS) and the Pedestrian Behavior Scale (PBS). We discovered that pedestrians' perceived inconvenience was positively correlated with transgression and positive behavior by pedestrians and it also positively correlated with the external affective demands (emotional engagement facet of TCS) while negatively correlated with the functionality (functional traffic system facet of TCS). We determined that the external affective demands were positively correlated with pedestrian risk behaviors (i.e., transgression, aggressive behaviors and lapses), internal requirements (traffic participants' skills facet of TCS) were positively correlated with positive behaviors, and functionality was negatively correlated with transgression and lapses. Moreover, the results indicate that the relationship between the inconveniences pedestrians perceive in city traffic and pedestrians' transgressive behavior was fully mediated by the functionality dimension of the traffic safety climate. Pedestrians' perceived inconvenience is an important factor that affects pedestrian behavior, and the influence of pedestrians' perceptions of the traffic safety climate cannot be disregarded.

Traffic accident risk assessment with dynamic microsimulation model using range-range rate graphs

Analysis of accidents that involve vehicles and pedestrians requires accurate reproduction of the dynamics of the vehicles and pedestrians immediately prior to and during the accident. In many cases, only centimeters and milliseconds separate survival from disaster, particularly when high-speed aggressive drivers and careless pedestrians are involved. In this paper we present a methodology for analyzing the dynamic interaction between drivers in conflict scenarios with pedestrians. We assess the safety of a traffic location's environment with a high-resolution, spatially explicit, dynamic agent-based simulation model - SAFEPED. Based on the resulting data, Range-Range Rate (R-RR) graphs are generated. These graphs provide compact, simple, and objective presentation of the dynamic interaction between vehicles and pedestrians. Significant traffic risk indicators such as Time-To-Collision, acceleration/deceleration rates, and minimal distances between vehicles and pedestrians are easily extracted from the R-RR graphs. These indicators can provide insights on particular traffic scenarios and can assist road planners and developers of traffic safety measures in understanding the dynamic behavior of drivers and pedestrians before and during a conflict scenario.

Viewpoints of pedestrians with and without cognitive impairment on shared zones and zebra crossings

Background

Shared zones are characterised by an absence of traditional markers that segregate the road and footpath. Negotiation of a shared zone relies on an individual’s ability to perceive, assess and respond to environmental cues. This ability may be impacted by impairments in cognitive processing, which may lead to individuals experiencing increased anxiety when negotiating a shared zone.

Method

Q method was used in order to identify and explore the viewpoints of pedestrians, with and without cognitive impairments as they pertain to shared zones.

Results

Two viewpoints were revealed. Viewpoint one was defined by “confident users” while viewpoint two was defined by users who “know what [they] are doing but drivers might not”.

Discussion

Overall, participants in the study would not avoid shared zones. Pedestrians with intellectual disability were, however, not well represented by either viewpoint, suggesting that shared zones may pose a potential barrier to participation for this group.

An evidence based method to calculate pedestrian crossing speeds in vehicle collisions (PCSC)

Pedestrian accident reconstruction is necessary to establish cause of death, i.e. establishing vehicle collision speed as well as circumstances leading to the pedestrian being impacted and determining culpability of those involved for subsequent court enquiry. Understanding the complexity of the pedestrian attitude during an accident investigation is necessary to ascertain the causes leading to the tragedy. A generic new method, named Pedestrian Crossing Speed Calculator (PCSC), based on vector algebra, is proposed to compute the pedestrian crossing speed at the moment of impact. PCSC uses vehicle damage and pedestrian anthropometric dimensions to establish a combination of head projection angles against the windscreen; this angle is then compared against the combined velocities angle created from the vehicle and the pedestrian crossing speed at the time of impact. This method has been verified using one accident fatality case in which the exact vehicle and pedestrian crossing speeds were known from Police forensic video analysis. PCSC was then applied on two other accident scenarios and correctly corroborated with the witness statements regarding the pedestrians crossing behaviours. The implications of PCSC could be significant once fully validated against further future accident data, as this method is reversible, allowing the computation of vehicle impact velocity from pedestrian crossing speed as well as verifying witness accounts.

Differences in road-crossing decisions between healthy older adults and patients with Alzheimer's disease

INTRODUCTION

This study investigated the differences in road-crossing behavior among healthy older adults and patients with Alzheimer's disease (AD).

METHOD

Twelve pedestrians with mild AD and 24 age-, gender-, and education-matched controls were examined with a battery of cognitive, visual, and motor tests. Using a simulated two-lane, one-way road-crossing situation, we determined the remaining time and safety margin for each participant in traffic situations involving different vehicle speeds (40 km/h vs. 60 km/h vs. 80 km/h), time gaps (5 s vs. 7 s vs. 9 s), and time of day (dusk vs. midday).

RESULTS

We found that patients with AD were more vulnerable to traffic crash while crossing the road than healthy older adults (Odds Ratio = 2.50, P < 0.05). Compared with healthy older adults, patients with AD were more severely affected by daylight conditions, faster vehicle speed, and shorter time gap. Participants in both groups had a significantly higher risk of unsafe crossing behavior if they had lower scores on the Mini-Mental State Examination (MMSE), Complex Figure Test - recall (CFT-Recall), Trail Making Test (TMT) B-A, Useful Field of View (UFOV) - total, and Visual Form Discrimination (VFD). We also found that when given a long enough time gap (9 s), patients with AD and healthy older adults used similar safe road-crossing behaviors, independent of other factors.

PRACTICAL APPLICATIONS

These results provide important suggestions for road design for patients with AD and healthy older adults during road-crossing.

The perception of Malaysian pedestrians toward the use of footbridges

OBJECTIVE

The footbridge is a vital structure in the road network and a cornerstone among crossing facilities. Yet, it suffers from low usage by pedestrians as they try to cross the street on the level. This study aims to analyze the perceptions of Malaysian pedestrians toward the use of footbridges with the consideration of different factors.

METHOD

The study was carried out by collecting data from field observation and questionnaire distribution on the street among the public. The data were statistically analyzed by applying multiple linear regression models and a series of chi-square tests.

RESULTS

The study found that the most influential factor cited by pedestrians in decision making regarding using a footbridge is the existence of an escalator. Being in a hurry and the fear of heights were significantly associated with choosing not to use a footbridge. Zebra crossing was chosen as the most favorable type of crossing facility by the majority of respondents. In addition, installation of a fence and barriers was proposed as an effective procedure to prevent jaywalking. To construct new and efficient footbridges in the future, the study suggests consideration of traffic volume, posted speed limit, and the number of lanes, because these are the most influential factors to predict the usage rate.

CONCLUSIONS

The study encourages decision makers and stakeholders to consider providing escalators for new footbridges to enhance the safety of pedestrians.

Pedestrian crossing behavior, an observational study in the city of Ushuaia, Argentina

OBJECTIVES

Pedestrian crashes are a critical problem in Latin American countries. However, little research has been published about pedestrians and even less about their behaviors in a naturalistic context. The objective of the present research was to explore risky pedestrian crossing behaviors in traffic intersections in an argentine city (Ushuaia). It is focused in different stages of the crossing process, traffic code violations, and other potentially risky behaviors such as distractions. A high frequency of risky behaviors among pedestrians was expected. Moreover, according to previous findings, it was hypothesized that men and younger pedestrians would show riskier behaviors.

METHODS

Participants were 802 pedestrians (53.9% females) observed at several intersections (with and without traffic lights) in the city of Ushuaia. Behaviors were codified following a standardized observation protocol. Observers documented information on behavior previous to, during, and after crossing. Gender and age were also registered. Data were gathered through video recording. Frequency analyses of observed behaviors were conducted for the total sample, as well as by gender and by age group. A general crossing risk index was calculated to facilitate comparisons between the genders and age groups. We conducted an analysis of variance to evaluate gender and age differences for this index.

RESULTS

A high proportion of risky behaviors were observed among pedestrians. The majority of pedestrian waited in the street (as opposed to on the sidewalk) before crossing, did not comply with traffic lights, or crossed outside the crosswalk. A large number of pedestrians were distracted while crossing. Men presented higher scores on risky behaviors than women. No differences were observed by age group.

CONCLUSIONS

The high level of risk behaviors during the different stages of street crossing is worrisome and reinforces the idea that pedestrians are responsible for many of the conflicts with motorists. Many of the risky behaviors seem to be associated with gender, which is in line with the previous literature showing more risk behaviors among men than among women. No differences were found for age group. Findings are interpreted considering some features of the Argentine road culture.

Pedestrian's exposure to road traffic crashes in urban environment: A case study of Peshawar, Pakistan

This study was aimed at exploring accident statistics and suggesting counter measures to mitigate road traffic crashes in Peshawar, Pakistan, and was conducted in 2015-16. Data was extracted from all 30 police stations in cantonment, city and rural circles for the 2003-12 period. A total of 3,280 crashes were reported, including 856(26%) fatal and 2,424(74%) non-fatal ones. Moreover, 602(69%) fatalities and 1,782(59%) injuries of overall road traffic fatalities and injuries during the period studied were borne by pedestrians. No regular annual pattern was noticed for overall and pedestrians' fatalities and injuries. Detailed RTCs' analysis, police officials' interviews and engineering judgement during field visits indicate that there is a dire deficiency of physical infrastructure for pedestrians, signage and markings. There is a need to improve post-crash evaluation and implement counter measures for speed control.

Display of required crossing speed improves pedestrian judgment of crossing possibility at clearance phase

At crosswalks with countdown timers, pedestrians arriving at the clearance phase tend to start crossing when the remaining time is too short. It is unclear whether this phenomenon is due to errors in judging the possibility to finish crossing before signal lights turning red. This study evaluated and compared pedestrians' accuracy in judgment of crossing possibility based on two cues: the amount of remaining time, and the minimum required speed to finish crossing within clearance phase (road width / remaining time). The results showed that pedestrians overestimated crossing possibility when they made judgments based on remaining time, especially when the road was narrow. By contrast, the display of required speed resulted in higher overall accuracy and lower false alarm rate, due to higher sensitivity to different crossing possibilities and more conservative set of response criterion. This advantage is consistent across different road widths. These findings suggest that pedestrians' risky decisions based on the countdown timers are partly induced by overestimation of crossing possibilities. The advantages of required-speed display over traditional countdown timers indicate a strong possibility to improve pedestrian judgments by information design.

Considering built environment and spatial correlation in modeling pedestrian injury severity

OBJECTIVE

This study looks at mitigating and aggravating factors that are associated with the injury severity of pedestrians when they have crashes with another road user and overcomes existing limitations in the literature by focusing attention on the built environment and considering spatial correlation across crashes.

METHOD

Reports for 6,539 pedestrian crashes occurred in Denmark between 2006 and 2015 were merged with geographic information system resources containing detailed information about the built environment and exposure at the crash locations. A linearized spatial logit model estimated the probability of pedestrians sustaining a severe or fatal injury conditional on the occurrence of a crash with another road user.

RESULTS

This study confirms previous findings about older pedestrians and intoxicated pedestrians being the most vulnerable road users and crashes with heavy vehicles and in roads with higher speed limits being related to the most severe outcomes. This study provides novel perspectives by showing positive spatial correlations of crashes with the same severity outcomes and emphasizing the role of the built environment in the proximity of the crash.

CONCLUSIONS

This study emphasizes the need for thinking about traffic calming measures, illumination solutions, road maintenance programs, and speed limit reductions. Moreover, this study emphasizes the role of the built environment, because shopping areas, residential areas, and walking traffic density are positively related to a reduction in pedestrian injury severity. Often, these areas have in common a larger pedestrian mass that is more likely to make other road users more aware and attentive, whereas the same does not seem to apply to areas with lower pedestrian density.

A vibrotactile wristband to help older pedestrians make safer street-crossing decisions

INTRODUCTION

Older pedestrians are overrepresented in fatal accidents. Studies consistently show gap-acceptance difficulties, especially in complex traffic situations such as two-way streets and when vehicles approached rapidly. In this context, the present research was aimed at assessing the effectiveness of a vibrotactile device and study older pedestrian's behavior when wearing the wristband designed to help them make safer street-crossing decisions.

METHOD

Twenty younger-old participants (age 60-69), 20 older-old participants (age 70-80) and 17 younger adults (age 20-45) carried out a street-crossing task in a simulated two-way traffic environment with and without a vibrotactile wristband delivering warning messages.

RESULTS

The percentage of decisions that led to collisions with approaching cars decreased significantly when participants wore the wristband. Benefits tended to be greater particularly among very old women, with fewer collisions in the far lane and when vehicles approached rapidly when they wore the wristband. But collisions did not fall to zero, and responses that were in accordance with the wristband advice went up to only 51.6% on average, for all participants. The wristband was nevertheless considered useful and easy to use by all participants. Moreover, behavioral intentions to buy and use such a device in the future were greater in both groups of older participants, but not among the younger adults.

PRACTICAL APPLICATIONS

This haptic device was able to partly compensate for some age-related gap-acceptance difficulties and reduce street-crossing risks for all users. These findings could be fruitfully applied to the design of devices allowing communication between vehicles, infrastructures, and pedestrians.

Modeling pedestrian crossing speed profiles considering speed change behavior for the safety assessment of signalized intersections

Pedestrian safety is one of the most challenging issues in road networks. Understanding how pedestrians maneuver across an intersection is the key to applying countermeasures against traffic crashes. It is known that the behaviors of pedestrians at signalized crosswalks are significantly different from those in ordinary walking spaces, and they are highly influenced by signal indication, potential conflicts with vehicles, and intersection geometries. One of the most important characteristics of pedestrian behavior at crosswalks is the possible sudden speed change while crossing. Such sudden behavioral change may not be expected by conflicting vehicles, which may lead to hazardous situations. This study aims to quantitatively model the sudden speed changes of pedestrians as they cross signalized crosswalks under uncongested conditions. Pedestrian speed profiles are collected from empirical data and speed change events are extracted assuming that the speed profiles are stepwise functions. The occurrence of speed change events is described by a discrete choice model as a function of the necessary walking speed to complete crossing before the red interval ends, current speed, and the presence of turning vehicles in the conflict area. The amount of speed change before and after the event is modeled using regression analysis. A Monte Carlo simulation is applied for the entire speed profile of the pedestrians. The results show that the model can represent the pedestrian travel time distribution more accurately than the constant speed model.

Examining how different measurement approaches impact safety outcomes in child pedestrian research: Implications for research and prevention

There has been a great deal of research aimed at understanding the causes of child pedestrian injury. Many different methods have been employed with the goal of designing simulations that produce rigorous assessment of children's behaviors without putting children at risk of actual pedestrian injury. Most research has assessed children's pre-crossing decision making and extrapolated crossing outcome measures from estimates of mean walking speed. This study explores the nature and extent of measurement bias that is introduced when average walking speed is used to produce estimates of outcomes versus measuring actual in-road behavior directly. Using a within-subjects design and a fully immersive virtual reality pedestrian simulator, both measures were taken. Comparisons based on regression models revealed the extent of differences in results produced by measurement bias. Results indicated that measurement bias is produced when average walking speed is used such that hits and high risk crossings are overestimated and missed opportunities are underestimated, resulting in an overall overestimate of children's risk for pedestrian injury. The discussion highlights how these two measurement approaches emphasize different underlying processes as determinants of child pedestrian injury risk.

Collective movements of pedestrians: How we can learn from simple experiments with non-human (ant) crowds

Introduction

Understanding collective behavior of moving organisms and how interactions between individuals govern their collective motion has triggered a growing number of studies. Similarities have been observed between the scale-free behavioral aspects of various systems (i.e. groups of fish, ants, and mammals). Investigation of such connections between the collective motion of non-human organisms and that of humans however, has been relatively scarce. The problem demands for particular attention in the context of emergency escape motion for which innovative experimentation with panicking ants has been recently employed as a relatively inexpensive and non-invasive approach. However, little empirical evidence has been provided as to the relevance and reliability of this approach as a model of human behaviour.

Methods

This study explores pioneer experiments of emergency escape to tackle this question and to connect two forms of experimental observations that investigate the collective movement at macroscopic level. A large number of experiments with human and panicking ants are conducted representing the escape behavior of these systems in crowded spaces. The experiments share similar architectural structures in which two streams of crowd flow merge with one another. Measures such as discharge flow rates and the probability distribution of passage headways are extracted and compared between the two systems.

Findings

Our findings displayed an unexpected degree of similarity between the collective patterns emerged from both observation types, particularly based on aggregate measures. Experiments with ants and humans commonly indicated how significantly the efficiency of motion and the rate of discharge depend on the architectural design of the movement environment.

Practical applications

Our findings contribute to the accumulation of evidence needed to identify the boarders of applicability of experimentation with crowds of non-human entities as models of human collective motion as well as the level of measurements (i.e. macroscopic or microscopic) and the type of contexts at which reliable inferences can be drawn. This particularly has implications in the context of experimenting evacuation behaviour for which recruiting human subjects may face ethical restrictions. The findings, at minimum, offer promise as to the potential benefit of piloting such experiments with non-human crowds, thereby forming better-informed hypotheses.

"Outta my way!" Individual and environmental correlates of interactions between pedestrians and vehicles during street crossings

Because pedestrian crash rates remain lower than other collision types, surrogate measures such as traffic interactions are now used in road safety research to complement crash history. Using naturalistic data collection, we sought to assess 1) the likelihood of occurrence of interactions between pedestrians and vehicles based on individual and crossing characteristics; and 2) differences in interaction characteristics between children, adult and senior pedestrians. Observations of pedestrian crossing behaviours (n=4687) were recorded at 278 crossings. For recorded interactions (n=843), information was collected to characterize the behaviours of involved parties. A mixed-effect logit regression model was performed to assess the factors associated with interactions. Chi-square tests evaluated differences between age groups and characteristics of observed interactions. Older adults were those more likely to be involved in an interaction event. Bicycle paths, different crossing surface material and one-way streets were significantly associated with fewer interactions with vehicles, while parked vehicles nearby and crossings on arterial roads were significantly associated with more interactions. Children and the elderly (80 years of age or more) did have distinct patterns of interaction, with more careful drivers/cyclists behaviours being observed towards children and lesser regulation compliance towards the elderly. Given the growing emphasis and adoption of active transportation in many cities, the number of interactions between pedestrians and vehicles during street crossings is likely to increase. Educating drivers and pedestrians to respect each other's space requires an understanding of where, between whom, and under what circumstances interactions occur. Such an approach can also help identify which engineering and enforcement programs are needed to ensure safe pedestrian crossings since interactions can be good markers of uncomfortable crossing situations that may deter walking and lead to more collisions.

Collective phenomena in crowds-Where pedestrian dynamics need social psychology

This article is on collective phenomena in pedestrian dynamics during the assembling and dispersal of gatherings. To date pedestrian dynamics have been primarily studied in the natural and engineering sciences. Pedestrians are analyzed and modeled as driven particles revealing self-organizing phenomena and complex transport characteristics. However, pedestrians in crowds also behave as living beings according to stimulus-response mechanisms or act as human subjects on the basis of social norms, social identities or strategies. To show where pedestrian dynamics need social psychology in addition to the natural sciences we propose the application of three categories-phenomena, behavior and action. They permit a clear discrimination between situations in which minimal models from the natural sciences are appropriate and those in which sociological and psychological concepts are needed. To demonstrate the necessity of this framework, an experiment in which a large group of people (n = 270) enters a concert hall through two different spatial barrier structures is analyzed. These two structures correspond to everyday situations such as boarding trains and access to immigration desks. Methods from the natural and social sciences are applied. Firstly, physical measurements show the influence of the spatial structure on the dynamics of the entrance procedure. Density, waiting time and speed of progress show large variations. Secondly, a questionnaire study (n = 60) reveals how people perceive and evaluate these entrance situations. Markedly different expectations, social norms and strategies are associated with the two spatial structures. The results from the questionnaire study do not always conform to objective physical measures, indicating the limitations of models which are based on objective physical measures alone and which neglect subjective perspectives.

Concept of an enhanced V2X pedestrian collision avoidance system with a cost function-based pedestrian model

OBJECTIVE

State-of-the-art collision avoidance and collision mitigation systems predict the behavior of pedestrians based on trivial models that assume a constant acceleration or velocity. New sources of sensor information-for example, smart devices such as smartphones, tablets, smartwatches, etc.-can support enhanced pedestrian behavior models. The objective of this article is the development and implementation of a V2Xpedestrian collision avoidance system that uses new information sources.

METHODS

A literature review of existing state-of-the-art pedestrian collision avoidance systems, pedestrian behavior models in advanced driver assistance systems (ADAS), and traffic simulations is conducted together with an analysis of existing studies on typical pedestrian patterns in traffic. Based on this analysis, possible parameters for predicting pedestrian behavior were investigated. The results led to new requirements from which a concept was developed and implemented.

RESULTS

The analysis of typical pedestrian behavior patterns in traffic situations showed the complexity of predicting pedestrian behavior. Requirements for an improved behavior prediction were derived. A concept for a V2X collision avoidance system, based on a cost function that predicts pedestrian near future presence, and its implementation is presented. The concept presented considers several challenges such as information privacy, inaccuracies of the localization, and inaccuracies of the prediction.

CONCLUSION

A concept for an enhanced V2X pedestrian collision avoidance system was developed and introduced. The concept uses new information sources such as smart devices to improve the prediction of the pedestrian's presence in the near future and considers challenges that come along with the usage of these information sources.

Pedestrian-driver communication and decision strategies at marked crossings

The aim of this work is to describe pedestrian-driver encounters, communication, and decision strategies at marked but unsignalised crossings in urban areas in the Czech Republic and the ways in which the parties involved experience and handle these encounters. A mixed-methods design was used, consisting of focus groups with pedestrians and drivers regarding their subjective views of the situations, on-site observations, camera recordings, speed measurements, the measurement of car and pedestrian densities, and brief on-site interviews with pedestrians. In close correspondence with the literature, our study revealed that the most relevant predictors of pedestrians' and drivers' behaviour at crossings were the densities of car traffic and pedestrian flows and car speed. The factors which influenced pedestrians' wait/go behaviour were: car speed, the distance of the car from the crossing, traffic density, whether there were cars approaching from both directions, various signs given by the driver (eye contact, waving a hand, flashing their lights), and the presence of other pedestrians. The factors influencing drivers' yield/go behaviour were: speed, traffic density, the number of pedestrians waiting to cross, and pedestrians being distracted. A great proportion of drivers (36%) failed to yield to pedestrians at marked crossings. The probability of conflict situations increased with cars travelling at a higher speed, higher traffic density, and pedestrians being distracted by a different activity while crossing. The findings of this study can add to the existing literature by helping to provide an understanding of the perception of encounter situations by the parties involved and the motives lying behind certain aspects of behaviour associated with these encounters. This seems necessary in order to develop suggestions for improvements. For instance, the infrastructure near pedestrian crossings should be designed in such a way as to take proper account of pedestrians' needs to feel safe and comfortable, as well as ensuring their objective safety. Thus, improvements should include measures aimed at reducing the speed of approaching vehicles (e.g. humps, speed cushions, elevated crossings, early yield bars, and narrow lanes), as this would enhance yielding by motor vehicles. Other measures that specifically rely on the subjective perception of different situations by the parties involved include the education and training of drivers, the aim of which is to promote their understanding and appreciation of pedestrians' needs and motives.

Pedestrian road crossing behavior (PEROB): Development and psychometric evaluation

OBJECTIVE

The aim of this study was to develop a theory-based questionnaire to measure road crossing attitudes and potentially risky pedestrian behavior.

METHODS

A cross-sectional validation study was carried out on a total sample of 380 young adults aged 18 to 25 years who live in Tehran, Iran. Data were collected from January 27 to May 20, 2015, using a self-administered structured pool of 76 items that was developed from research on the theory of planned behavior. A panel of subject-matter experts evaluated the items for content validity index and content validity ratio, and the questionnaire was pretested. Exploratory factor analysis (EFA) was performed to test construct validity. The Cronbach's alpha coefficient and intraclass correlation coefficient (ICC) analyses were done to assess internal consistency and stability of the scale.

RESULTS

From the initial 76 items, 38 items were found to be appropriate for assessing the pedestrian road crossing behavior (PEROB) of young adults in Tehran. A 9-factor solution revealed an exploratory factor analysis that jointly accounted for 63.8% of the variance observed. Additional analyses also indicated acceptable results for the internal consistency with Cronbach's alpha value ranging from 0.67 to 0.88 and ICC values ranging from 0.64 to 0.96.

CONCLUSIONS

This psychometric evaluation of a self-administered instrument resulted in a reliable and valid instrument to assess young adult pedestrians' self-reported road crossing attitudes and behaviors in Tehran. Further development of the instrument is needed to assess its applicability to other road users, particularly older pedestrians.

Training the elderly in pedestrian safety: Transfer effect between two virtual reality simulation devices

OBJECTIVES

A virtual-reality training program has been developed to help older pedestrians make safer street-crossing decisions in two-way traffic situations. The aim was to develop a small-scale affordable and transportable simulation device that allowed transferring effects to a full-scale device involving actual walking.

METHODS

20 younger adults and 40 older participants first participated in a pre-test phase to assess their street crossings using both full-scale and small-scale simulation devices. Then, a trained older group (20 participants) completed two 1.5-h training sessions with the small-scale device, whereas an older control group received no training (19 participants). Thereafter, the 39 older trained and untrained participants took part in a 1.5-h post-test phase again with both devices.

RESULTS

Pre-test phase results suggested significant differences between both devices in the group of older participants only. Unlike younger participants, older participants accepted more often to cross and had more collisions on the small-scale simulation device than on the full-scale one. Post-test phase results showed that training older participants on the small-scale device allowed a significant global decrease in the percentage of accepted crossings and collisions on both simulation devices. But specific improvements regarding the way participants took into account the speed of approaching cars and vehicles in the far lane were notable only on the full-scale simulation device.

DISCUSSION

The findings suggest that the small-scale simulation device triggers a greater number of unsafe decisions compared to a full-scale one that allows actual crossings. But findings reveal that such a small-scale simulation device could be a good means to improve the safety of street-crossing decisions and behaviors among older pedestrians, suggesting a transfer of learning effect between the two simulation devices, from training people with a miniature device to measuring their specific progress with a full-scale one.

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

OBJECTIVES

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.

Road crossing behavior under traffic light conflict: Modulating effects of green light duration and signal congruency

A large number of pedestrians and cyclists regularly ignore the traffic lights to cross the road illegally. In a recent analysis, illegal road crossing behavior has been shown to be enhanced in the presence of incongruent stimulus configurations. Pedestrians and cyclists are more likely to cross against a red light when exposed to an irrelevant conflicting green light. Here, we present experimental and observational data on the factors moderating the risk associated with incongruent traffic lights. In an observational study, we demonstrated that the conflict-related increase in illegal crossing rates is reduced when pedestrian and cyclist green light periods are long. In a laboratory experiment, we manipulated the color of the irrelevant signals to expose participants to different degrees of incongruency. Results revealed that individuals' performance gradually varied as a function of incongruency, suggesting that the negative impact of a conflicting green light can be reduced by slightly adjusting its color. Our findings highlight that the observation of real-world behavior at intersections and the experimental analysis of psychological processes under controlled laboratory conditions can complement each other in identifying risk factors of risky road crossing behavior. Based on this combination, our study elaborates on promising measures to improve safety at signalized intersections.

The influence of pedestrian countdown signals on children's crossing behavior at school intersections

Previous studies have shown that pedestrian countdown signals had different influences on pedestrian crossing behavior. The purpose of this study was to examine the effects of the installation of countdown signals at school intersections on children's crossing behavior. A comparison analysis was carried out on the basis of observations at two different school intersections with or without pedestrian countdown signals in the city of Jinan, China. Four types of children's crossing behavior and child pedestrian-vehicle conflicts were analyzed in detail. The analysis results showed that using pedestrian countdown timers during the Red Man phase led to more children's violation and running behavior. Theses violators created more conflicts with vehicles. However, pedestrian countdown signals were effective at helping child pedestrian to complete crossing before the red light onset, avoid getting caught in the middle of crosswalk. No significant difference was found in children who started crossing during Flashing Green Man phase between the two types of pedestrian signals. Moreover, analysis results indicated that children who crossed the road alone had more violation and adventure crossing behavior than those had companions. Boys were found more likely to run crossing than girls, but there was no significant gender difference in other crossing behavior. Finally, it's recommended to remove countdown at the end of the Red Man phase to improve children's crossing behavior and reduce the conflicts with vehicles. Meanwhile other measures are proposed to improve children safety at school intersections.

How do children learn to cross the street? The process of pedestrian safety training

OBJECTIVE

Pedestrian injuries are a leading cause of child death and may be reduced by training children to cross streets more safely. Such training is most effective when children receive repeated practice at the complex cognitive-perceptual task of judging moving traffic and selecting safe crossing gaps, but there is limited data on how much practice is required for children to reach adult levels of functioning. Using existing data, we examined how children's pedestrian skills changed over the course of 6 pedestrian safety training sessions, each composed of 45 crossings within a virtual pedestrian environment.

METHODS

As part of a randomized controlled trial on pedestrian safety training, 59 children ages 7-8 crossed the street within a semi-immersive virtual pedestrian environment 270 times over a 3-week period (6 sessions of 45 crossings each). Feedback was provided after each crossing, and traffic speed and density were advanced as children's skill improved. Postintervention pedestrian behavior was assessed a week later in the virtual environment and compared to adult behavior with identical traffic patterns.

RESULTS

Over the course of training, children entered traffic gaps more quickly and chose tighter gaps to cross within; their crossing efficiency appeared to increase. By the end of training, some aspects of children's pedestrian behavior was comparable to adult behavior but other aspects were not, indicating that the training was worthwhile but insufficient for most children to achieve adult levels of functioning.

CONCLUSIONS

Repeated practice in a simulated pedestrian environment helps children learn aspects of safe and efficient pedestrian behavior. Six twice-weekly training sessions of 45 crossings each were insufficient for children to reach adult pedestrian functioning, however, and future research should continue to study the trajectory and quantity of child pedestrian safety training needed for children to become competent pedestrians.

Risk factors in road crossing among elderly pedestrians and readiness to adopt safe behavior in socio-economic comparison

This research examines the Health Promotion Behavior (HPB) models regarding elderly pedestrians' behaviors and attitudes. We studied cognitive-psychological variables, such as risk estimation, self-efficacy and demographic variables and compared elderly pedestrians' attitudes and behaviors in a city with higher socio-economic level (Tel Aviv) versus a city with low socio-economic level (Beer Sheva). We expected to find more problematic behaviors among elderly pedestrians in the low socio-economic city compared to the high socio-economic city, and also less feeling of self-efficacy, and lessened awareness of the risks, that leads to lessened willingness to adopt preventive behaviors. The research was conducted in two studies. The first study was based on observations on 2591 pedestrians in six similar crosswalks in both cities. It revealed that pedestrians in the high socio-economic city demonstrated safer road crossing patterns than in the low socio-economic city and that elderly pedestrians reveal safer crossing patterns than younger pedestrians. We found an interaction of location and age due to greater gap of safe behaviors of elderly and young pedestrians in the high socio-economic city than in the low socio-economic city. In Tel Aviv elderly adhere to the crossing rules much more than the young while in Beer Sheva elderly and young people are almost similar in their crossing patterns. The second study used questionnaires that have been completed by 143 elderly in both cities. The questionnaires referred to (a) demographic variables such as gender, age, marital status, education, socio-economic level, (b) variables related to the affiliation to the main culture such as migration, date of migration, knowledge in Hebrew (local language) and connectivity to media and (c) cognitive as well as psychological variables related to the decline to adopt healthy behaviors based on Schwarzer and Fuchs (1995). This part also indicated that elderly in Tel Aviv have higher awareness of risk factors on the road and their limitations as elderly pedestrians. The HPB (Pender, 1996) emphasizes the role of risk perception as a predictor of willingness to adopt preventive strategies. Moreover, elderly pedestrians in Beer Sheva compared to those in Tel Aviv estimated their ability to cross safely the streets as higher.

Putting Up a Big Front: Car Design and Size Affect Road-Crossing Behaviour

Previous research suggests that people tend to see faces in car fronts and that they attribute personality characteristics to car faces. In the present study we investigated whether car design influences pedestrian road-crossing behaviour. An immersive virtual reality environment with a zebra crossing scenario was used to determine a) whether the minimum accepted distance for crossing the street is larger for cars with a dominant appearance than for cars with a friendly appearance and b) whether the speed of dominant-looking cars is overestimated as compared to friendly-looking cars. Participants completed both tasks while either standing on the pavement or on the centre island. We found that people started to cross the road later in front of friendly-looking low-power cars compared to dominant-looking high-power cars, but only if the cars were relatively large in size. For small cars we found no effect of power. The speed of smaller cars was estimated to be higher compared to large cars (size-speed bias). Furthermore, there was an effect of starting position: From the centre island, participants entered the road significantly later (i. e. closer to the approaching car) and left the road later than when starting from the pavement. Similarly, the speed of the cars was estimated significantly lower when standing on the centre island compared to the pavement. To our knowledge, this is the first study to show that car fronts elicit responses on a behavioural level.

Morphology of pedestrian roads and thermal responses during summer, in the urban area of Bucheon city, Korea

The purpose of this study was to elucidate the effect of urban morphology representing sky view factor (SVF) on urban microclimate and on human thermal responses. The physical environments and the changes in body temperatures as well as psychological responses were investigated in summer in Bucheon, Korea. The dry bulb temperature ranged from 31.5 °C at SVF 0.082 site to 35.7 °C at SVF 0.922 site. Most of the environmental elements were statistically correlated to the SVF: the dry bulb temperature R (2) = 0.602, UVB R (2) = 0.556 and the illumination level R (2) = 0.609. The mean skin temperature increased up to 36.0 °C at the SVF 0.940 site and decreased to 33.9 °C at the SVF 0.082 site. The mean skin temperature was statistically correlated to the SVF (p = 0.005). However, the core body temperature was not correlated to SVF because of time delay effect to the previously exposed thermal environment. In the investigation of thermal acceptability, only 5 % of subjects were dissatisfied with the road that was covered with plentiful trees; in contrast, approximately 50 % of subjects were dissatisfied with the road with poor solar obstacles in the summer. The thermal stress was affected by the urban morphology, and the plentiful urban greening improved thermal comfort.

Towards an integrated approach of pedestrian behaviour and exposure

In this paper, an integrated methodology for the analysis of pedestrian behaviour and exposure is proposed, allowing to identify and quantify the effect of pedestrian behaviour, road and traffic characteristics on pedestrian risk exposure, for each pedestrian and for populations of pedestrians. The paper builds on existing research on pedestrian exposure, namely the Routledge microscopic indicator, proposes adjustments to take into account road, traffic and human factors and extends the use of this indicator on area-wide level. Moreover, this paper uses integrated choice and latent variables (ICLV) models of pedestrian behaviour, taking into account road, traffic and human factors. Finally, a methodology is proposed for the integrated estimation of pedestrian behaviour and exposure on the basis of road, traffic and human factors. The method is tested with data from a field survey in Athens, Greece, which used pedestrian behaviour observations as well as a questionnaire on human factors of pedestrian behaviour. The data were used (i) to develop ICLV models of pedestrian behaviour and (ii) to estimate the behaviour and exposure of pedestrians for different road, traffic and behavioural scenarios. The results suggest that both pedestrian behaviour and exposure are largely defined by a small number of factors: road type, traffic volume and pedestrian risk-taking. The probability for risk-taking behaviour and the related exposure decrease in less demanding road and traffic environments. A synthesis of the results allows to enhance the understanding of the interactions between behaviour and exposure of pedestrians and to identify conditions of increased risk exposure. These conditions include principal urban arterials (where risk-taking behaviour is low but the related exposure is very high) and minor arterials (where risk-taking behaviour is more frequent, and the related exposure is still high). A "paradox" of increased risk-taking behaviour of pedestrians with low exposure is found, suggesting that these pedestrians may partly compensate in moderate traffic conditions due to their increased walking speed.

Review of safety and mobility issues among older pedestrians

Although old people make up an extremely vulnerable road-user group, older pedestrians' difficulties have been studied less extensively than those of older drivers, and more knowledge of this issue is still required. The present paper reviews current knowledge of older-adult problems with the main components of pedestrian activity, i.e., walking and obstacle negotiation, wayfinding, and road crossing. Compared to younger ones, old pedestrians exhibit declining walking skills, with a walking speed decrease, less stable balance, less efficient wayfinding strategies, and a greater number of unsafe road crossing behaviors. These difficulties are linked to age-related changes in sensorial, cognitive, physical, and self-perception abilities. It is now known that visual impairment, physical frailty, and attention deficits have a major negative impact on older pedestrians' safety and mobility, whereas the roles of self-evaluation and self-regulation are still poorly understood. All these elements must be taken into consideration, not only in developing effective safety interventions targeting older pedestrians, but also in designing roads and cars. Recent initiatives are presented here and some recommendations are proposed.

Evacuation of Pedestrians with Two Motion Modes for Panic System

In this paper, we have captured an underlying mechanism of emergence of collective panic in pedestrian evacuations by using a modification of the lattice-gas model. We classify the motion of pedestrians into two modes according to their moods. One is gentle (mode I), the other is flustered (mode II). First, to research the cause for crowd, we fix the motion modes of pedestrians and increase the proportion of pedestrians with motion mode II (ρ_II). The simulation results show that the pedestrians with motion mode II are lack of evacuation efficiency and cause more casualties. Further, we use the SIS (susceptible-infective-susceptible) model to describe the spreading of the panic mood. The system can be in the high-mix state when the infection probability λ is greater than a fuzzy threshold. In addition, the distances S from wounded people to the exit are researched, the number of wounded people gets maximum at the internal S = 5 ∼ 10, which is independent of ρ_II and λ. This research can help us to understand and prevent the emergence of collective panic and reduce wounds in the real evacuation.