The Impact of Commercial Parking Utilization on Cyclist Behavior in Urban Environments

With growing freight operations within the United States, there continues to be a push for urban streets to accommodate trucks during loading and unloading operations. Currently, many urban locations do not provide loading and unloading zones, which results in trucks parking in places that can obstruct roadway infrastructure designated to vulnerable road users (e.g., pedestrians and cyclists). In an effort to understand the implications of these truck operations, a bicycle simulation experiment was designed to evaluate the impact of commercial vehicle loading and unloading activities on safe and efficient bicycle operations in a shared urban roadway environment. A counter-balanced, factorial design was chosen to explore three independent variables: commercial vehicle loading zone (CVLZ) sizes with three levels (no CVLZ, Min CVLZ, and Max CVLZ), courier position with also three levels (No courier, behind the truck, beside the truck), and loading accessories (Acc) with two levels (no Acc, and with Acc). Cyclist’s velocity and lateral position were used as performance measures. Data were obtained from 48 participants (24 women) resulting in 864 observations in 18 experimental scenarios. Linear Mixed-Effects Models (LMM) were developed to examine the effect of each independent variable level on bicyclist performance.Results from LMM model suggest that loading zone size had the greatest effect on cyclist’s divergence. Additionally, when the courier was walking beside the truck, cyclist’s velocity significantly dropped to almost one m/sec in compared when the courier located behind the truck. The presence of accessories had the lowest influence on both velocity and lateral positions of cyclists. In the no CVLZ scenarios, the delivery vehicle was parked at the bike lane, therefore; cyclists had to choose between using the travel lane or the sidewalk. About one-third of participants decided to use the sidewalk. These findings could support better roadway and CVLZ design guidelines, which will allow our urban street system to operate more efficiently, safely, and reliably for all users.     

A controlled clinical comparison of attention performance in children with ADHD in a virtual reality classroom compared to standard neuropsychological methods.

In this initial pilot study, a controlled clinical comparison was made of attention perforance in children with attention deficit-hyperactivity disorder (ADHD) in a virtual reality (VR) classroom. Ten boys diagnosed with ADHD and ten normal control boys participated in the study. Groups did not significantly differ in mean age, grade level, ethnicity, or handedness. No participants reported simulator sickness following VR exposure. Children with ADHD exhibited more omission errors, commission errors, and overall body movement than normal control children in the VR classroom. Children with ADHD were more impacted by distraction in the VR classroom. VR classroom measures were correlated with traditional ADHD assessment tools and the flatscreen CPT. Of note, the small sample size incorporated in each group and higher WISC-III scores of normal controls might have some bearing on the overall interpretation of results. These data suggested that the Virtual Classroom had good potential for controlled performance assessment within an ecologically valid environment and appeared to parse out significant effects due to the presence of distraction stimuli.     

The implications of low quality bicycle paths on gaze behavior of cyclists: A field test

Unlike for car driving and walking, the visual behavior during cycling is poorly documented. The aim of this experiment was to explore the visual behavior of adult bicycle users ‘in situ’ and to investigate to what extent the surface quality affects this behavior. Therefore cycling speed, gaze distribution and gaze location of five participants were analyzed on a high and a low quality bicycle track. Although there was no difference in cycling speed between the low and the high quality cycling path, there was an apparent shift of attention from distant environmental regions to more proximate road properties on the low quality track. These findings suggest that low quality bicycle tracks may affect the alertness and responsiveness of cyclists to environmental hazards.     

Evaluation of user behavior and acceptance of an on-bike system

In this study, users’ acceptance of an on-bike system that warns about potential collisions with motorized vehicles as well as its influence on cyclists’ behavior was evaluated. Twenty-five participants took part in a field study that consisted of three different experimental tasks. All participants also completed a follow-up questionnaire at the completion of the three-task series to elicit information about the acceptance of the on-bike system. In the experiment phase, participants were asked to ride the bicycle throughout a circuit and to interact with a car at an intersection. Participants completed three laps of the circuit. The first lap involved no interaction with the car and served the purpose of habituation. In the second and third laps participants experienced a conflict with an incoming car at an intersection. In the second lap, the on-bike device was not activated, while in the third lap, participants received a warning message signaling the imminent conflict with the car. We compared the difference in user’s behavior between the second lap (conflict with a car without the warning of the on-bike system) and the third lap (conflict with a car with the warning of the on-bike system). Results showed that, when entering the crossroad, participants were more likely to decrease their speed in case of warning of the on-bike system. Further, the on-bike system was relatively well accepted by the participants. In particular, participants did not report negative emotions when using the system, while they trusted it and believed that using such technology would be free from effort. Participants were willing to spend on average 57.83 € for the system. This study highlights the potential of the on-bike system for promoting bicycle safety.     

Risk compensation theory and bicycle helmets – Results from an experiment of cycling speed and short-term effects of habituation

It has been suggested that the safety benefits of bicycle helmets are limited by risk compensation. The current study contributes to explaining whether the potential safety effects of bicycle helmets are reduced by cyclists’ tendency to cycle faster when wearing them (as a result of risk compensation), and if this potential reduction can be associated with a change in perceived risk. A previous study (Fyhri & Phillips, 2013) showed that non-routine helmet users did not increase their speed immediately after being given a helmet to wear, while routine helmet users cycled more slowly. The current study tests whether the previously found reduction in speed in response to helmet removal – as an indirect indicator of risk compensation – could be established in non-routine helmet users, after a period of habituation while cycling with a helmet.We did this by conducting a randomized crossover trial, in which we used GPS-derived speed calculations and self-reported risk perception. To test the effect of habituation, we used a design where each participant took part in two rounds with a break between and each round having two trips. We collected the data in June 2015. Non-routine helmet users (N = 31) were recruited in the field (along cycle routes in Oslo), and through a sample drawn from the Falck National register of bicycle owners. In the first phase of the study, all participants were asked to complete a test route (2.4 km downhill) with and without a helmet. In the second phase of the experiment, conducted after 1.5–2 h, the same participants again completed the test route with and without a helmet. In the time between the first and second phases of the experiment, all participants were given helmets, and told to use them on a predefined bicycle route.Habituation to the helmet between the first and second phases of the experiment did not produce any decrease (with helmet removal) in speed, on top of the habituation that occurred while cycling down the hill (the order effect). Mean speed difference for cycling with/without a helmet before the break was −0.76 km/h, after the break this difference was 0.32 km/h; 95% CIs [−0.5, 2.9] and [−0.9, 1.5]. We argue that risk compensation is an unlikely effect of using a bicycle helmet, and probably cannot explain any adverse effects related to helmet legislation.     

Evaluating bicyclists’ risk perception using video clips: Comparison of frequent and infrequent city cyclists

Hazard and risk perception has been studied extensively among car drivers, and their link to crash involvement is established. Bicyclists, in particular, are vulnerable road users. Better understanding of their risk and hazard perception could help to improve their traffic safety.In this study, we investigated the risk perception of bicyclists in a city environment. Two groups of bicyclists were compared: 19 frequent and 19 infrequent bicyclists. Participants were shown video clips taken with a camera attached to the handlebar of a bicycle, and they were asked to continuously indicate with a slider how much caution the situation needed.The frequent cyclists had more frequent rises in the caution estimate, which suggest that they anticipated or detected more hazards than infrequent cyclists. This is in line with the classical hazard perception results, which link the car driving experience to faster and more accurate hazard perception. The overall level or caution was not directly related to the rise event rate or bicycling frequency. Those cyclists who reported typically cycling faster than others showed elevated overall level of caution on sidewalks compared with others, but there was no difference on bike paths.     

Reducing Inappropriate Bicycle Parking Through Persuasive Communication

In this study, the effectiveness of persuasive communication in reducing inappropriate bicycle parking was investigated. We hypothesized that persuasive communication aimed at promoting behavioral intention with respect to reducing the frequency of inappropriate bicycle parking would not actually achieve its objective, but that persuasive communication aimed at promoting implementation intention, as well as behavioral intention, would be successful. We conducted a field experiment using 99 participants who were daily bicycle users. They were randomly assigned to a control group and to 3 experimental groups. The results indicated that participants in the with-advice group and planning group had stronger implementation intentions, and thus reduced their incidence of inappropriate bicycle parking, than did the control and the without-advice groups. However, there were no differences in behavioral intention.     

The perception of bicycle crashes with and without motor vehicles: Which crash types do older and middle-aged cyclists fear most?

Several studies have focused on the perceived risk of bicycle crashes (irrespective of crash types) and concluded that cycling near high volumes of motor vehicles deters people from cycling. The perceived risk of bicycle crash types (with or without motor vehicles) has not yet been studied. Cyclists, both in countries with low and high levels of cycling participation, are substantially more likely to sustain severe injuries in single-bicycle crashes than in bicycle-motor vehicle crashes. This questionnaire study sets out to compare which bicycle crash types are perceived to cause most hospitalizations among cyclists. The study comprised cyclists over 55 years in the Netherlands, and over 40 years in the Belgian regions of Flanders (a region with high cycling participation), Brussels and Wallonia (regions with low cycling participation). The majority of cyclists (60%) perceive bicycle-motor vehicle crashes cause most hospitalizations among cyclists. This percentage is greatest in the areas of Brussels and Wallonia and lowest in the Netherlands. Cyclists who were involved in a bicycle-motor vehicle crash themselves are more likely to regard this crash type as the most common cause of hospitalizations among cyclists, while cyclists over 60 years who were involved in a crash without a motor vehicle are more likely to perceive that crash type as the most common cause. The smaller perception bias in the study areas with higher cycling participation – particularly the Netherlands and to a somewhat lesser degree Flanders – is probably due to bicycle infrastructure being more separated from high-speed motor traffic, leaving cyclists less exposed. The outcomes show that cyclists underestimate the likelihood of severe injuries due to single-bicycle crashes. New interventions should raise the awareness of the risk of single-bicycle crashes and provide solutions to avoid such crashes.     

Theory of mind ability in high socially anxious individuals

Background/Objectives: Research has demonstrated an association between social anxiety and impaired Theory of Mind (ToM). We assess whether ToM deficits occur even at a subclinical level of social anxiety and whether group differences in ToM performance are consistent with interpretation bias. We also explore potential reasons as to why socially anxious individuals may perform differently on ToM tasks.

Methods/Design: Undergraduate participants high (HSA; n?=?78) and low (LSA; n?=?35) in social anxiety completed a task of ToM decoding, the Reading the Mind in the Eyes (MIE), a task of ToM reasoning, the Movie for the Assessment of Social Cognition (MASC), and a post-task questionnaire about their experience completing the MASC.

Results: HSAs performed marginally worse than LSAs on the MIE on neutrally valenced trials, and their pattern of errors may be consistent with a negative interpretation bias. HSAs and LSAs did not differ overall in performance on the MASC, though HSAs reported experiencing more confusion and distress than LSAs during the task, and this distress was associated with more MASC errors for HSA participants only. These results provide insight into the nature of ToM ability in socially anxious individuals and highlight important avenues for future research.     

How do warnings influence cyclists' reaction to conflicts? Comparing acoustic and vibro-tactile warnings in different conflicts on a test track

An on-bike warning system has great potential to increase safety of cyclists. For an effective warning system, the implementation of warning signals is fundamental. However, more knowledge about the cyclist specific design of warnings and the influence of warnings on the cyclist is needed. To analyze the benefit of warnings in conflicts and the reaction pattern of cyclists we conducted a test-track experiment. We evaluated the data of 62 participants who were divided into three warning groups (between-subjects) and encountered different situations (within-subjects). The warning groups either received acoustic, vibro-tactile or no warnings. The situation variable consisted of three conflicts and two false warnings in the groups with warnings.We measured significantly shorter reaction times of persons who received acoustic and vibro-tactile warnings compared to the persons without warning. Furthermore, acoustic warnings led to shorter reaction times compared to vibro-tactile warnings. The reaction pattern was described by different bicycle dynamics variables. It was mostly influenced by the situation and rarely by the warning group. Based on the velocity curves and reaction times we identified learning effects describing how the warned participants adopted the warning system over the five situations.These findings indicate that a warning system offers great safety benefits to cyclists. Based on the current results, acoustic warnings are recommended when an urgent reaction is required.     

Accuracy, error, and bias in predictions for real versus hypothetical events

Participants made predictions about performance on tasks that they did or did not expect to complete. In three experiments, participants in task-unexpected conditions were unrealistically optimistic: They overestimated how well they would perform, often by a large margin, and their predictions were not correlated with their performance. By contrast, participants assigned to task-expected conditions made predictions that were not only less optimistic but strikingly accurate. Consistent with predictions from construal level theory, data from a fourth experiment suggest that it is the uncertainty associated with hypothetical tasks, and not a lack of cognitive processing, that frees people to make optimistic prediction errors. Unrealistic optimism, when it occurs, may be truly unrealistic; however, it may be less ubiquitous than has been previously suggested.     

Cyclist strategies and behaviour at intersections. Conscious and un-conscious strategies regarding positioning

Severe and even fatal accidents between cyclists and motor vehicles commonly occur at intersections. Many of these accidents occur with right-turning vehicles, with drivers not observing an adjacent cyclist. Few structured investigations exist regarding the interaction between cyclist and motor vehicle, and factors in need of study are how infrastructure and vehicle properties affect human decision-making and cycling behaviour. Therefore, a bicycle simulator study was performed, where vehicle type, presence of lane markings and lane width were systematically varied in a scenario with a cyclist approaching a vehicle from behind, at a signalized city intersection. 33 participants cycled through 8 intersection variants each. Data on cycling trajectories, stopping points and speed was coupled with survey data from the participants, and semantically categorized verbal responses to questions regarding strategy for choice of stopping point. Results show that all three factors (vehicle type, lane markings and available vehicle-adjacent space) significantly affects cyclists’ behaviour and conscious strategies. Participants were more cautious in the presence of a truck than a car, reflected in choice of position when cycling and stopping, and in explicit verbalisations regarding perilous aspects of the situation and their conscious and strategic choice of positioning. Available lateral space also affected stop positions and feeling of safety (expressed verbally). Presence of bicycle lane markings made the cyclists inclined to continue into the space to the right of the vehicle. This was revealed by their positioning and speed, and also apparent in the verbal expressions, especially the positive remarks on the situation and conditions. However, the perceived comfort with lane markings present was actually lower than when they were missing. Cyclist type (slow, moderate, or fast) matters with the self-reported faster cyclists being more prone to stop to the right than the slower one.     

Modeling cyclist acceleration process for bicycle traffic simulation using naturalistic data

Cycling is a healthy and sustainable form of transportation. The recent increase of daily cyclists in Sweden has triggered broad interest in finding how policies and measures may facilitate the planning of bicycle traffic in the urban area. However, in comparison to car traffic, bicycle traffic is still far from well understood. This study is part of the research effort to investigate microscopic cyclist behavior, model bicycle traffic and finally build a simulation tool for applications in transport planning. In particular, the paper focuses on representing bicycle movements when the cyclist doesn’t interact with others. The cyclist acceleration behavior is modeled using naturalistic GPS data collected by eleven recruited commuter cyclists. After filtering the large amount of data, cyclist trajectories are obtained and acceleration profiles are abstracted. A mathematical model is proposed based on the dataset, and three model forms are estimated using the maximum likelihood method with Laplace and Normal error terms. While the model with more parameters shows superior performance, the simplified ones are still capable of capturing the trends in the acceleration profiles. On the other hand, the study also introduces social economic characteristics of cyclists to explain the model parameters and they show significant effects. However, the cyclist population being investigated in the study is still limited, and more convincing results can be obtained when the data collection effort is extended to larger population with more variable cyclist characteristics.     

Cognitive styles: errors in directional judgments

Previous studies on spatial memory have shown that, in judging direction, participants are more accurate and faster when a map is aligned with the perspective of the spatial layout they had learned (alignment effect). Rossano and Warren (1989 Perception 18 215-229) have shown that when participants have to do a contra-aligned judgment they can either answer correctly, or make alignment or mirror-image errors. We think that the kind of response depends on the different way in which people acquire environmental knowledge: landmark, route, and survey. We hypothesise that landmark and route participants show alignment effects and make, respectively, alignment errors and mirror-image errors, whereas survey participants do not show an alignment effect. An experiment is reported in which participants performed three tasks in order to distinguish their cognitive style. We selected thirty landmark, thirty route, and twenty-eight survey participants. They were then submitted to directional judgment tasks to verify whether the alignment effect was present and to observe the kind of responses. The results revealed that survey participants did not show an alignment effect, and that the kind of errors could depend on the directional judgment task participants had to do, and not only on the cognitive style.     

Characteristics of older cyclists (65+) and factors associated with self-reported cycling accidents in the Netherlands

Cycling supports the mobility, health and independency of the ageing population. However, older cyclists have an increased injury risk. On average, the risk of older people to sustain an injury in a cycling accident is three times higher per cycling kilometre than for middle-aged people and the injury risk increases with age. In comparison with middle-aged cyclists (<65 years), the risk of hospitalization is more than four times as high for older cyclists (≥65 years). The aim of this study was to reveal characteristics of older cyclists in general and to explore which of these characteristics are associated with self-reported cycling accidents from age 59. More than eight hundred older cyclists (>65 years) filled out a questionnaire, which included questions on demographics, bicycle specifications and personal characteristics. By means of a logistic regression, the relationship between personal factors and self-reported bicycle falls were studied. The univariate models showed that age, physical and mental impairments, bicycle model, living environment, feelings of uncertainty of the cyclist and changed cycling behaviour (such as more patience, lower speed) were related to falling off a bicycle. From the multivariate model we can conclude that several factors are associated with falling off a bicycle in the older population: (1) every year the cyclists becomes one year older (from the age of 65), the chance they have fallen increases with 7.3%, (2) If cyclists have mental impairments, the chance they have fallen increases with a factor 2.5, (3) if cyclists were less than completely confident the chance they have fallen increases with factor 1.8, (4) if cyclists live in a rural environment compared to an urban environment the chance they have fallen increases with a factor 2.1. In conclusion, demographic, cycling and personal factors can be related to increased self-reported fall risk. It is advised to take these factors into account when implementing new cycling related safety measures.     

Compensatory behaviour of visually impaired cyclists in everyday settings

This study investigated whether visually impaired cyclists, compared to cyclists without visual limitations, take other, potentially safer routes to destinations in their own living environment and whether they ride at a lower speed. In total, 19 matched pairs of a visually impaired cyclist and a normally sighted peer from the same neighbourhood recorded their everyday bicycle rides, using GPS action cameras. In addition, they completed an ‘assigned ride’, a ride for which only a starting and an ending point were provided by the researcher. A risk-assessment procedure showed that the route taken by visually impaired cyclists during this assigned ride was not less risky than the route taken by the normally sighted cyclists. Analysis of the everyday rides showed that, on average, cyclists with a visual impairment more frequently (i.e. for longer periods) cycled at a speed below 10 km/h compared to cyclists without visual impairment. Also, the visually impaired participants’ cruising speed was 1.4 km/h lower than that of their normally sighted counterparts. In conclusion, no evidence was found that visually impaired cyclists compensate strategically by taking different, potentially safer routes than normally sighted cyclists when riding in their own environment. They may (unconsciously) compensate tactically for their visual function limitations by riding at a lower speed when necessary. Mobility trainers in vision rehabilitation as well as road designers could apply these findings to optimise the cycling mobility of visually impaired people.     

Analysis of cycling skill: A cognitive approach

Riding a bicycle can be considered as a combination of perceptual-motor and cognitive tasks. The task is divided into three functional levels: control, manoeuvring and strategic. Relevant (cognitive) abilities at the first two levels must be acquired and automatized through extensive experience. The processes which are not yet automatized may claim attention and will, therefore, interfere with other processes demanding attention. In this experiment, subjects of various ages and bicycling experience participated. The hypothesis was verified that novice cyclists cannot accomplish traffic-relevant cognitive tasks while they ride a bicycle; possible countermeasures were discussed.     

Cycling under the influence of alcohol in Germany

Cyclists have a relatively high risk of being injured in traffic accidents. In Germany, statistics have shown that cyclists injured in police-reported traffic accidents are often found to have cycled with high blood alcohol levels. Relevant research has discussed the ability of the Theory of Planned Behavior (TPB; Ajzen, 1991), deterrence factors, and habitual behavior to predict unsafe and rule-violating behavior in traffic. To promote safer cycling, the relative contributions of these predictors must be determined to design efficient countermeasures. In an online survey, N = 353 participants reported cycling and drinking behaviors for 1 week and answered questions on the TPB, deterrence, and additional predictors. Perceived social norms were quite permissive and perceived behavioral control when cycling under the influence (CUI) of alcohol was quite high. Furthermore, a third of the cyclists reported CUI. Participants with experience of CUI reported having consumed large amounts of alcohol before cycling. High levels of cycling, a permissive attitude, and greater alcohol consumption per drinking episode predicted the number of CUI trips. The amount of alcohol consumed before one CUI trip was predicted by high perceived behavioral control when CUI, a high level of need for stimulation, and higher habitual alcohol consumption per drinking episode. Deterrence factors were found to have no influence on reported CUI. Overall, the findings suggested that Germans who habitually drink a large amount of alcohol are not deterred from CUI in the same manner that they would be from driving under the influence (DUI). The generally permissive perceived social norms did not differentiate between CUI and non-CUI cyclists, which indicated that a societal effort is required to balance the mismatch between CUI and DUI. In addition, changing the general drinking behaviors of highly educated Germans who cycle, would be beneficial for their health.     

Updating in working memory: a comparison of good and poor comprehenders

In this research, we examined the relation between reading comprehension and success in a working memory updating task. We tested the hypotheses that poor comprehenders' deficiencies are associated with a specific difficulty in the working memory updating process, particularly in controlling for information that is no longer relevant. In the first experiment, groups of poor and good comprehenders, ages 8-11 years, were administered a working memory updating task. In the second experiment a year later, a subgroup of participants involved in the first experiment was tested with a different updating task. In both experiments, poor comprehenders had less accurate recall performance and made more intrusion errors than did good comprehenders. Moreover, distinguishing intrusion errors on the basis of their permanence in memory, we found that poor comprehenders were more likely to intrude items that were maintained longer in memory than were good comprehenders. This type of error predicted reading comprehension abilities better than did working memory recall. This suggests that the relation between reading comprehension and working memory is mediated by the ability to control for irrelevant information.     

Comparing perception of signals in different modalities during the cycling task: A field study

Cyclists are considered to be amongst the most vulnerable road users and the number of cyclists involved in crashes is increasing. One possibility to improve bicycle safety is the implementation of assistance systems, for instance by providing the information needed to avoid critical situations. However, it is not known how and what kind of signals can reliably be transmitted to cyclists, in particular as warnings. This study has the objective to investigate which signal type dependent of the modality and the route type can be perceived during the cycling task. Therefore, we conducted a semi-naturalistic cycling study with 56 participants where a 10 km long, pre-defined route was individually cycled while 36 signals (visual, auditory and vibro-tactile) were transmitted. The participants signalled the perception of a signal by pressing a button. Response rates differed significantly between signal modalities. While auditory signals performed best closely followed by vibro-tactile signals, visual signals were frequently missed. The route type had an effect on the perception of the signals. The influence of the route segments with haptic interference was not expected to be this large on the perception of vibro-tactile signals. The obtained results indicate how and in which situations the different modalities are suited to transmit information to cyclists.