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Analysis of heart rate variability amongst cyclists under perceived variations of risk exposure
Abstract
Cycling as a mode of travel provides an opportunity for many people to increase their levels of regular physical activity and contribute to their mental and physical health. Heart rate is often used as a means of measuring the intensity and energy expenditure of physical activity. However, heart rate is also linked to emotional factors such as anxiety and fear. Perceptions of risk due to external factors such as other road users and infrastructure may arouse such emotions in urban cyclists. The present study set out to investigate whether or not perceptions of risk among urban cyclists may lead to increased heart rates. Cyclists completed a test route in normal traffic conditions in Cork, Ireland and heart rates and self-reported risk ratings were recorded in real time. Evidence was found of a link between perceptions of risk and heart rates. This raises questions regarding the use of heart rate to estimate exercise intensity and energy expenditure during urban cycling. The perceptions of cyclists of their safety in relation to various road elements on familiar routes were also assessed, as well as specific events which they perceive to be high in risk. The results indicate that incidents involving car traffic and busy roads which offer no protection from interaction with car traffic are associated with greatest perceptions of risk.
... 4. Examined a physiological response as part of understanding bike riders' subjective bicycling experiences (defined above). For example, a study could have examined bike riders' heart rate as a proxy of their perceived stress in response to riding in congested urban environments (Doorley et al., 2015). Here, heart rate is the physiological response and bicyclist stress is the subjective experience. 5. Conducted a primary study involving their own data collection and analysis 6. Published in English Studies were excluded if: ...
... In nine studies, HR was used to measure subjective experience (Dastageeri et al., 2019;Doorley et al., 2015;Fyhri & Phillips, 2013;Gorgul et al., 2019;Hale et al., 2019;Pejhan et al., 2021;Rybarcyzk et al., 2020). HR was commonly used as a measure of subjective stress (n = 5), although HR was also used to measure happiness and fear (Dastageeri et al., 2019) or rider comfort (Rybarcyzk et al., 2020). ...
... Rybarcyzk et al. (2020) used HR per second as their unit of analysis. Doorley al. (2015) used interbeat intervals (IBI), the time in-between successive heart beats, measured in milliseconds, as their unit of analysis. Peijan et al. (2021) created their own stress index based on raw HR data (see Supplementary Material for formula and calculations). ...
Feeling unsafe, stressed, and uncomfortable while bike riding are key barriers that prevent people from riding more. Examining these perceptions is important for increasing bicycling. The recent rise in wearable devices has coincided with research using bike riders’ physiological responses to measure their subjective experiences while riding. However, the types of physiological responses used to quantify bike riders’ experiences and how well these responses compare to individual perceptions of riding experience gathered through interviews or surveys remains unknown. This scoping review aimed to address these knowledge gaps and identified five key findings: i) The main physiological responses used to measure subjective rider experience were heart rate variability, heart rate, and skin conductance; ii) Where physiological and non-physiological measures of subjective experience have been compared, statistical comparisons showed weak associations and descriptive comparisons showed moderate to large degrees of variation in the number of identified moments of stress; and iii) Physiological responses were predominantly used as measurements of psychological stress. We conclude that further work is needed to determine whether physiological responses are a valid measure of subjective riding experience, and to examine a wider range of feelings that people might experience while bike riding.
... The impact on cyclists of bicycle facilities and related road infrastructure was the main target of studies using ANS measures (Caviedes & Figliozzi, 2018;Cobb, Jashami, & Hurwitz, 2021;Doorley et al., 2015;Fitch, Sharpnack, & Handy, 2020;Teixeira et al., 2020;Werner, Resch, & Loidl, 2019). ...
... Stress-related cardiovascular response of cyclists was also investigated (Doorley et al., 2015;Fitch et al., 2020). In one study, among five road environments tested, only the local road with no centreline and low car speed/volumes consistently provided greater HRVsuggesting that "bicycle boulevard" designs (where traffic is calmed and bicyclists are given travel priority) may reduce stress bicycling environments (Fitch et al., 2020). ...
... For roads that provide important connections for vehicles (collectors/arterials), reducing outside traffic lane widths and increasing bike lane widths are likely to reduce bicyclist stress. Furthermore, another fully controlled experiment (Doorley et al., 2015) found a linear trend between cyclists' HR and busy roads without a bicycle lane or roundabouts where the cyclist continued straight on. ...
There has been a growing interest in understanding the interdependencies between urbanisation and mental health. Although transportation in cities is complex and of foremost importance to support the mobility of goods and passengers, little is known about how it relates to individual psychological distress. This review aims to provide an up-to-date synthesis of research evidence about the influence of transport infrastructure and operational performance (congestion, delays and reliability) on mental health/wellbeing. It is structured around three main interacting concepts that determined the search/selection of articles: identification of the above-mentioned transport-related exposures; use of psychological and physiological validated instruments; and the outcome on mental health/wellbeing. Ultimately, 69 studies were identified involving an empirical quantitative focus that met the inclusion criteria. We summarise the instruments most reported in these studies and the findings linking transport indicators and psychological and physiological outcomes. Across the review, we identified evidence of the contribution of key transport infrastructure, congestion and delay indicators on negative affective states and psychophysiological distress. Regarding transport reliability, the scarce number of studies identified did not allow for drawing similar firm conclusions. We conclude by discussing some limitations and providing recommendations for future research and policy-making agendas.
... The development of mobile sensing technologies has enabled mobility data collection from a variety of modalities. In this line of research, a number of naturalistic studies have investigated bicyclists' behaviors and physiological responses, such as HR, heart rate variability (HRV) [19], and gaze [47]. For example, the changes in ambient light levels can affect bicyclists' perception of the environment by changing the gaze reactions [62]. ...
... In general, studies have shown that an increase in stress level is associated with an increase in HR, and a decrease in RMSSD features [58,33,39]. More specifically, in bicycling studies, an association has been found between perceptions of risk and HR [19,23]. For instance, a naturalistic study in Ireland showed that situations bicyclists perceive to be risky are likely to elicit higher HR responses. ...
... For instance, a naturalistic study in Ireland showed that situations bicyclists perceive to be risky are likely to elicit higher HR responses. This study also found that busy roads and roundabouts without bike lanes were perceived as more dangerous and risky compared to roads where cyclists are separated from traffic [19]. ...
As a healthier and more sustainable way of mobility, cycling has been advocated by literature and policy. However, current trends in bicyclist crash fatalities suggest deficiencies in current roadway design in protecting these vulnerable road users. The lack of cycling data is a common challenge for studying bicyclists' safety, behavior, and comfort levels under different design contexts. To understand bicyclists' behavioral and physiological responses in an efficient and safe way, this study uses a bicycle simulator within an immersive virtual environment (IVE). Off-the-shelf sensors are utilized to evaluate bicyclists' cycling performance (speed and lane position) and physiological responses (eye tracking and heart rate (HR)). Participants bike in a simulated virtual environment modeled to scale from a real-world street with a shared bike lane (sharrow) to evaluate how introduction of a bike lane and a protected bike lane with pylons may impact perceptions of safety, as well as behavioral and psycho-physiological responses. Results from 50 participants show that the protected bike lane design received the highest perceived safety rating and exhibited the lowest average cycling speed. Furthermore, both the bike lane and the protected bike lane scenarios show a less dispersed gaze distribution than the as-built sharrow scenario, reflecting a higher gaze focus among bicyclists on the biking task in the bike lane and protected bike lane scenarios, compared to when bicyclists share right of way with vehicles. Additionally, heart rate change point results from the study suggest that creating dedicated zones for bicyclists (bike lanes or protected bike lanes) has the potential to reduce bicyclists' stress levels.
... To address the limitations of self-reported PSC, there has been increasing interest in objective physiological measures of a psychological stress response for in situ evaluations of PSC (Berger and Dörrzapf, 2018;Caviedes and Figliozzi, 2018;Doorley et al., 2015;Fitch et al., 2020;Jones et al., 2016;Nuñez et al., 2018;Zeile et al., 2016). In addition to avoiding some of the reliability and validity issues of self-reported PSC, dynamic physiological stress marker measurements can be combined with GPS and video data for highresolution (in space and time) analysis of potential factors affecting PSC. ...
... A. Bigazzi et al. 2018;Rybarczyk et al., 2020), or participant self-reporting (Doorley et al., 2015). Traffic volume was inferred through time of day (Caviedes and Figliozzi, 2018;Nuñez et al., 2018) or measured as the number of passing vehicles in synchronous video (Fitch et al., 2020). ...
... Werner et al. (2019) compared the rate of "moments of stress" (based on skin conductance and temperature thresholds) per km across four routes, without further discrimination of specific stressors. Doorley et al. (2015) conducted a field study with 8 participants to determine relationships between HR and self-reported perceived risk, without identifying specific stressors. They then collected self-reported risk data from another group of 20 participants without physiological sensors over the course of a week, to investigate self-reported stressor events and environments. ...
Understanding perceptions of safety and comfort (PSC) while walking or cycling is essential to accommodating and encouraging active travel, but current measures of PSC, primarily surveys, suffer from validity and reliability issues. Physiological markers of stress like electrodermal activity and heart rate variability have been proposed as alternative, objective measures of PSC. This paper presents a literature summary and conceptual framework examining the use of physiological stress markers during walking and cycling. The existing studies of active traveller stress markers report inconsistent findings and account for limited controls. We propose a comprehensive conceptual framework to describe the array of dynamic stimuli experienced during active travel, with complex appraisals and multidimensional stress responses that feedback to travel behaviour and stimuli exposure, and culminate in a set of physiological outcomes triggered by activation of the autonomic nervous system – all moderated by numerous personal and trip-related factors. The key challenge of inferring traffic-related fear or discomfort from physiological markers measured on-road is potential confounding effects of: (1) non-traffic factors that induce or modify stress responses, (2) traffic factors that induce stress responses not associated with safety or comfort, and (3) personal and environmental factors that directly influence physiological measurements outside of a stress response. No physiological stress marker has yet been shown to be reliable for on-road active travellers, particularly not for inter-subject comparisons. Physiological markers have the potential to provide high-resolution, objective information about pedestrian and cyclist PSC, but further research, particularly controlled experiments, and more precise study framing are needed to ensure validity and address moderating and confounding factors.
... While these initial three methodologies provide beneficial information into understanding implied stress, little is known about the behavior (e.g., bicyclists velocity, vertical displacement of bicyclists while riding) of bicyclists and their actual stress. Currently, there have been a few naturalistic studies conducted to evaluate bicyclist's behavior and physiological responses (e.g., heart rate variability, galvanic skin response) to varying roadway, facility, time of day, and event conditions; however, how those physiological measurements correlate to actual stress continues to be challenged and researched (Doorley et al., 2015;Vieira et al., 2016;Caviedes et al., 2017;Fitch et al., 2017;Teixeira et al., 2020;. Both heart rate variability and galvanic skin response measurements have been used as surrogate measures to quantify stress, but these studies have limitations that include the inability to control for roadway and environmental factors and inconclusive understanding of correlation between physiological responses and actual stress. ...
... Currently, there are only a few studies that have investigated bicyclist's behavior and physiological responses while riding in-field (Doorley et al., 2015;Vieira et al., 2016;Caviedes et al., 2017;Fitch et al., 2017;Teixeir et al., 2020). These studies used heart rate variability (HRV) and galvanic skin responses (GSR) as performance measures to determine bicyclist physiological responses to events while riding. ...
... Doorley et al. conducted a study in Cork, Ireland to evaluate how risks while cycling related to heart rate variability (Doorley et al., 2015). The study measured bicyclists heart rate variability while riding in three different cycling conditions and had participants conduct risk rating questionnaires and travel diaries to validate and understand the cyclist's experience. ...
Population growth increase of vehicle ownership, and development patterns have resulted in greater levels of congestion, pollution, and crash frequency. A proposed solution to lessen current transportation system demands is to increase the share of bicycle trips. Furthermore, as cycling is perceived by some as both a dangerous and stressful mode of transportation, understanding the factors that lead to less comfortable and stressful riding, can help drive bicycle infrastructure development. To establish a more robust understanding of the behaviors of bicyclists and how infrastructure design and operations influence them, a bicycle simulator was used to evaluate bicyclist performance measures of velocity, horizontal displacement, and physiological responses (i.e., galvanic skin response) while riding in varying roadway conditions. Results showed that bicyclists in the bike lane condition , had a GSR reading 1.77 peaks per min less than when cycling in the no bike lane condition. When bicyclists were in no bike lane condition, the GSR reading was not affected by vehicle speed but it was affected by the vehicular volume. Additionally, females felt less comfortable when riding in either bike condition, even though they reported that they were ''Strong and Fearless" riders. The methodology used for this study sets forth the foundation for future research that could evaluate varying facility designs and a wider range of individuals.
... Studying bicyclist stress through human physiology is in the proof-of-concept research stage. To our knowledge, two peer reviewed publications (Caviedes & Figliozzi, 2018;Doorley et al., 2015), one conference paper (Vieira, Costeira, Brand, & Marques, 2016), and one non-peer reviewed research report (Jones, Chatterjee, Spinney, Street, Van Reekum, Spencer, & Beale, 2016) are the only existing studies examining bicyclist stress as we have defined it. Doorley et al. (2015) used monitors to record participants' heart rates (HR) during a bicycling task in Cork, Ireland. ...
... To our knowledge, two peer reviewed publications (Caviedes & Figliozzi, 2018;Doorley et al., 2015), one conference paper (Vieira, Costeira, Brand, & Marques, 2016), and one non-peer reviewed research report (Jones, Chatterjee, Spinney, Street, Van Reekum, Spencer, & Beale, 2016) are the only existing studies examining bicyclist stress as we have defined it. Doorley et al. (2015) used monitors to record participants' heart rates (HR) during a bicycling task in Cork, Ireland. They correlated HR to subjective safety ratings at specific locations along a bicycling course. ...
... 12-13). Only a small number of studies have attempted to measure psychological stress of bicyclists (Caviedes & Figliozzi, 2018;Doorley et al., 2015;Jones et al., 2016;Vieira et al., 2016). Because of the wide degree of experimental differences between this study and those prior studies, it is difficult to compare them. ...
Understanding how road environments stress bicyclists (and prospective bicyclists) has important implications for road design and network planning. With the rise of wearable bio-sensing technology, the potential for measuring real-time environmental acute stress is emerging. In this naturalistic cross-over field experiment, we investigate bicyclist stress through heart rate variability (HRV). We examine the relationship between HRV and the road environment through a series of multilevel statistical models. Results suggest that participants’ HRV are only certain to differ on one (the local road) of five road environments tested. The differences in participants’ HRV between two collectors and two arterials are far more tenuous. We discuss the validity of HRV and other biometrics for assessing stress and discuss how HRV and other biometrics might help improve our understanding of bicyclists’ perceptions of road environments.
... Sympathetic excitation caused by risks dominates the heart's nervous activity, causing changes in physiological responses associated with cardiac activity. The inter-beat interval (IBI) in HRV was related to risk perception [34], and low frequency (LF) and high frequency (HF) reflect the activity of the sympathetic and parasympathetic nervous systems, respectively [35]. At the same time, methods for monitoring physiological activity have been widely used in various studies related to human health, perception, and emotion [36]. ...
... The ear clip of the pulse sensor should be clipped to the ear, and the sensor should be attached to the wrist with a wrist strap (Figure 1c,d). The HRV was calculated from the IBI [34]. The standard deviation of all NN intervals (SDNN), The NN interval is a way of saying the cardiac time interval between peaks, the square root of the mean of the sum of the squares of differences between adjacent NN intervals (RMSSD), and short-term measures of the frequency domain, including ultralow frequency (ULF) power (0-0.0033 ...
... For further verification, we performed a paired t-test on the results, as seen in Table 4. We use the p-value of 0.05 to distinguish the level of significance [27,31,34]. The results of the t-test showed that alarm sounds ...
Due to differences in cognitive ability and physiological development, the evacuation characteristics of children are different from those of adults. This study proposes a novel method of using wearable sensors to collect data (e.g., electrodermal activity, EDA; heart rate variability, HRV) on children's physiological responses, and to continuously and quantitatively evaluate the effects of different types of alarm sounds during the evacuation of children. In order to determine the optimum alarm for children, an on-site experiment was conducted in a kindergarten to collect physiological data for responses to different types of alarm sounds during the evacuation of 42 children of different ages. The results showed that: (1) The alarm sounds led to changes in physiological indicators of children aged 3-6 years, and the effects of different types of alarm sounds on EDA and HRV activities were significantly different (p < 0.05). Skin conductance (SC), skin conductance tonic (SCT) and skin conductance level (SCL) can be used as the main indicators for analysing EDA of children in this experiment (p < 0.05), and the indicators of ultralow frequency (ULF) and very low frequency (VLF) for HRV were not affected by the type of alarm sounds (p > 0.05). (2) Unlike adults, kindergarten children were more susceptible to the warning siren. The combined voice and warning alarm had optimal effects in stimulating children to perceive risk. (3) For children aged 3-6 years, gender had a significant impact on children's reception to evacuation sound signals (p < 0.05): Girls are more sensitive than boys in receiving evacuation sound signals, similar to findings of studies of risk perception of adult males and females. In addition, the higher the age, the greater the sensitivity to evacuation sound signals, which accords with results of previous studies on the evacuation dynamics of children.
... Changes in heart rates have proven to be one of the most effective markers of stress (Palanisamy, Murugappan, & Yaacob, 2013) as it's been associated with: fear (Levenson, 1992), anger (Kahneman, 1973), anxiety (Mesken, Hagenzieker, Rothengatter, & de Waard, 2007), and comfortability (Pecchinenda, 1996). When bicyclists traverse a mixed-mode urban environment they experience a range of these physiological responses which invariably influence heart rates (Doorley et al., 2015). Other past research supports this claim. ...
... Other past research supports this claim. Doorley et al., (2015) investigated heart rate levels of thirteen bicyclists in three scenarios and found that in the controlled experiment, increased heart rates were associated with elevated traffic levels which was verified by way of their subjective risk perceptions assessed separately. Additionally, a recent study from Kyriakou et al., (2019) utilized wearable biosensors to investigated bicycling and walking stress via heart rate variations. ...
The current research set out to measure the moderating effect that urban design may have on bicyclist physiology while in transition. Focusing on the hilly City of Wuppertal, Germany, we harnessed bicyclists with mobile sensors to measure their responses to urban design metrics obtained from space syntax, while also adjusting for known traffic, terrain, and contextual factors. The empirical strategy consisted of exploratory data analysis (EDA), ordinary least squares (OLS), and a local regression model to account for spatial autocorrelation. The latter model was robust (R² = 68%), and showed that two statistically significant (p < 0.05) urban design factors influenced bicyclist physiology. Controllability, a measure of how spatially dominated a space is, increased bicyclist responses (i.e., decreased comfortability); while integration, which is related to accessibility and connectivity, had the opposite effect. Other noteworthy covariates included one-way streets and density of parked automobiles: these exerted a negative influence on bicyclist physiology. The results of this research ultimately showed that nuanced urban designs have a moderate influence on bicycling comfort. These outcomes could be utilized by practitioners focused on implementing appropriate interventions to increase bicyclist comfort levels and this mode share.
... Selected Model Parameter SummariesThe scant but growing evidence(Doorley et al. 2015;Jones et al. 2016;Caviedes and Figliozzi 2018;Teixeira et al. 2020;Fitch, Sharpnack, and Handy 2020;Werner, Resch, and Loidl 2019;Zeile et al. 2016) that bicyclist stress can be estimated through physiological markers should be scrutinized and ...
This paper describes the relationship between a physiological marker of stress (heart rate variability) and survey-based stress responses from a cross-over real-world bicycling experiment. The analysis shows that while heart rate variability was inversely associated with survey-based estimates of stress, large uncertainty in the relationship indicates carefully controlled experiments are still needed before we can be confident that bicyclist stress can be measured through heart rate variability.
... Several factors associated with stress have been recognized in the psychology and sociology literatures, including internal and external environment perturbations, future expectancy, negative neighborhood characteristics, and even social threats (Oken et al., 2015;Zhang, 2018). However, it is important to highlight that only a few studies have tested the relationship between bicycle commuting and stress in adults (Avila-Palencia et al., 2017;Doorley et al., 2015;Kaplan and Prato, 2016;. Even fewer have questioned whether there is any relationship between environmental factors and stress, using physiological signals (Fitch et al., 2017;Kyriakou et al., 2019;Nuñez et al., 2018). ...
There is substantial evidence that the environment has an important impact on the use of bicycles. Changes in the built environment, such as cycling infrastructure provision, usually aim at improving the efficiency, en-joyability and safety of cycling. They can also shape affective responses, for instance by triggering or preventing stress situations during cycling. The repeated occurrence of intensely stressful events may make actual cyclists more likely to abandon cycling and deter prospective cyclists from actually taking up this form of mobility. Therefore, using a novel approach, based on stress biomarker measurements obtained directly from cyclists, the objective of this study is to investigate the relationship between urban environment and cyclists' stress. It also investigates if different types of cycling infrastructures in the contexts of two different countries and in five different cities have different relationships with stress. Using a stress sensor, 70 young adults were invited to cycle along a standard route in Oxford, London (the United Kingdom), Amsterdam, Houten and Groningen (the Netherlands). These routes were around 6 km long and had a wide range of characteristics. Multilevel logistic regression analysis indicates that the probability of stressful events occurring is significantly lower on physically segregated cycle paths than on cycle paths on streets, with cycling on general use streets falling in-between these extremes. We also find higher probabilities of stress for primary roads compared to tertiary roads, at intersections than on straight roads, on cobbled and off-road surfaces compared to asphalt, and in noisier places. Models for the individual cities suggested that the relationship between cycling infrastructure and the likelihood of stressful events occurring may depend on the local context. Only for noise conditions, intersection types and cycling infrastructures were the effects consistent across the cities. These findings may be useful for urban infrastructure planning and management, indicating specific attributes that should be adjusted to make cycling less stressful.
... The quasi-naturalistic approach using instrumented bike is relatively new to the field of cycling research. [13,14,15] and some studies are exploring the relationship between physiological responses, perceptions and actual behavior or events. The present study extends this scope further by using a quasi-natural experiment to investigate the relationship of passing events with physiological responses and perceptions of cyclists. ...
... Several factors associated with stress have been recognised in the psychological and sociological literature. However, it is important to highlight that just a few studies tested the relationship between bicycle commuting and stress in adults (Avila-Palencia et al. 2017;Doorley et al. 2015;Kaplan and Prato 2016;H. Wang, Palm, et al. 2016). ...
The health benefits of cycling are larger than the risks, but by increasing the safety risk, the assumption is that people will ride less. Stress is related to safety and security as it is a reaction of the organism aiming to survive or avoid pain and discomfort. The aim of this study is to present a conceptual framework to investigate the stress of commuting cyclists and to discuss how it can benefit from technology. The proposed framework contains variables related to personal characteristics, urban environment, traffic characteristics, natural environment, social environment, temporal information, cyclists' characteristics and characteristics of the trip. In addition, a range of technologies to assess them while on the move, thus allowing real life design experiments, is shown. Having a conceptual model and the technologies to assess it, we hope to support future research in this field contributing both to scientific knowledge and to planning/implementing public policies.
... Also, other physiological variables such as heart rate (HR) heart rate variability (HRV), inter-beat interval (IBI) and skin temperature (ST) are worthwhile to study in the future. A sympathetic nervous system aroused by significant risk innervates the heart which results in changes in physiological responses that are related to heart activity such as HR, HRV, and IBI (Doorley et al., 2015). Also, previous studies found that changes in sympathetic nervous activities are related to ST changes (Azevedo et al., 2017). ...
Risk perception is known as a critical step in workers' safety decision-making process. However, current approaches to assess workers' perceived risk include surveys and interviews which are post hoc, subjective, and cumbersome to implement at construction sites. To address the issues associated with these methods, the authors propose a novel approach for the continuous and quantitative assessment of workers' perceived risk using physiological responses acquired from wearable sensors. With this background, this study aims to investigate the potential of using physiological sensory data (e.g., electrodermal activity (EDA)) collected from off-the-shelf wristband typed sensors to understand construction workers' perceived risk during their ongoing work. To achieve this objective, 30 h of physiological sensory data were collected from eight construction workers during their ongoing work. The results indicate that: (1) electrodermal response (EDR), which refers to short-term changes in EDA, shows significant differences between low and high-risk activities; (2) high-risk activities significantly affect workers' EDR during their ongoing work. The main contribution of this study is to show the feasibility of using wearable sensors to understand workers' perceived risk in construction sites continuously. Considering the complexity and dynamicity of workers' tasks on construction sites, the development of an objective , continuous, and non-intrusive method for monitoring workers' physiological responses is expected to contribute to a more in-depth understanding of construction workers' perceived risk.
... Off-road facilities tend to reduce perceived cycling risk (Parkin et al. 2007;Winters et al., 2012;Doorley et al., 2015;McNeil et al., 2015). They are perceived as the most suitable environment to cycle with children (Aldred, 2015). ...
Raising cycling use lies at the heart of sustainable mobility policies. Many reviews and original researches are published evaluating a safe environment for cycling. This paper records and compares published research on objective and subjective safety when cycling. In most cases objective safety is affected by attributes which also affect subjective safety like traffic volume, synthesis and speed. Interestingly some papers show reduction of objective safety where subjective safety raises. The provision of dedicated cycling infrastructure at roundabouts , or traffic light presence proves to be detrimental. Also, surprisingly, more accidents occur on off-road trails where traffic is absent.
... These perspectives do not see divergences between expert and public views about risk as implying the public must be wrong. Indeed, growing evidence suggests people are relatively good at comparing situation-specific cycling risks, their judgements corresponding reasonably well to expert opinion (e.g. Bill et al., 2015; Doorley et al., 2015; Johnson et al., 2014; Sanders, 2013). At the same time, many see on-road cycling in the UK as unacceptably risky (DfT, 2014). ...
This paper explores cyclists’ experiences of non-injury incidents, arguing that these are important for cycling experience and uptake as well as for injury prevention. It discusses different types of non-injury incident collected in a recent survey of UK cyclists. These are everyday occurrences that in some cases have a substantially negative impact on cycling experiences. This article explores the impact of different incident types on people cycling both immediately and in the future. It analyses what near misses tell us about cyclists’ experience of problems related to road user behaviour and culture, and infrastructural conditions for cycling. The paper explores what cyclists experiencing near misses think might have prevented them. Based on this and on a comparison with common types of injury incidents, recommendations are made for policy and future research.
... The data collection methods for 13 perceived cycling safety studies have also been summarised by Lawson et al. (2013) to include: video recordings, video simulations, completion of a test course, interviews and questionnaires (see Doorley et al. (2015) for a novel application of heart rate monitors in the assessment of perceived risk). However, only two of the studies reviewed by Lawson et al. (2013) considered the characteristics of the cyclists: Møller & Hels (2008) and Noland (1995). ...
Cycling is the most energy-efficient mode of transport and can bring extensive environmental, social and economic benefits. Research has highlighted negative perceptions of safety as a major barrier to the growth of cycling. Understanding these perceptions through the application of novel place-sensitive methodological tools such as mental mapping could inform measures to increase cyclist numbers and consequently improve cyclist safety. Key steps to achieving this include: (a) the design of infrastructure to reduce actual risks and (b) targeted work on improving safety perceptions among current and future cyclists.
Understanding what environments are comfortable (and perceived as safe) for bicyclists is essential for increasing bicycling, particularly for non-experienced riders. Surveys probing people’s qualitative perceptions about bicycling environments can inform bicycle planning in important ways. In this study we use survey data from an on-line video experiment to analyze bicycling comfort and its relationship with person-level and road-level variables. We use an existing survey of students, faculty, and staff at UC Davis (n = 3089) who rated video clips of bicycling facilities in different environments based on their perceived comfort as a part of the annual UC Davis Campus Travel Survey (CTS). The video clips come from a variety of urban and semi-rural roads around the San Francisco Bay Area where bicycling rates vary. Our results indicate considerable effects of socio-demographics and attitudes on absolute video ratings, but we find relative agreement about which videos are most comfortable and uncomfortable across our sample population segments. Presence of bike infrastructure and low speed roads are especially important in generating higher comfort ratings. However, our results suggest that even the best designed on-road bike facilities (according to attributes in our data) are unlikely to provide a comfortable bicycling environment for those without a predisposition to bicycle. Nonetheless, our results provide guidance for improving roads with on-street bike facilities where protected or separated facilities may not be suitable. We discuss these results in the context of design standards for bicycling and methods for prioritizing bike infrastructure investments.
Analysis of the variations of heart activity during different human activities is an important area of research in sport sciences. Therefore, in this paper, we evaluated the variations of heart activity for 23 subjects while sitting, hand biking, walking, and running. Since the obtained R-R time series (as the indicator of heart rate variability (HRV)) has a complex structure that contains information, we employed fractal dimension, sample entropy, and Shannon entropy for our analysis. According to the results, doing a harder activity causes a more significant alteration in the complexity and information content of HRV. The results of statistical analyses also verified the obtained results. Similar investigations can be conducted in case of other activities to evaluate the variations in heart activity in different conditions.
This chapter is concerned with a research project in which collaboration between psychology, medicine and engineering was necessary to assess the physiological and the psychological perceptions of risk in cyclists, comparing both to determine their impact on wearable technology that measures bodily signals of stress. Here we describe the research design and process, highlighting how insights from all these disciplines were necessary to carry out the project and interpret the conclusions.
Physical activity and ventilation rates have an effect on an individual's dose and may be important to consider in exposure-response relationships; however, these factors are often ignored in environmental epidemiology studies. The aim of this study was to evaluate methods to estimate the inhaled dose of air pollution and understand variability, in the absence of a true gold standard metric. Five types of methods were identified: (1) methods using (physical) activity types; (2) methods based on energy expenditure, METs (metabolic equivalents of task) and oxygen consumption; (3) methods based on heart rate or (4) breathing rate; and (5) methods that combine heart and breathing rate. Methods were compared using a real-life dataset of 122 adults who wore devices to track movement, black carbon air pollution and physiological health markers for three weeks in three European cities. Different methods to estimate minute ventilation performed well in relative terms with high correlations among different methods. But in absolute terms, ignoring increased ventilation during day to day activities could lead to an underestimation of daily dose by a factor 0.08 to 1.78. There is no single best method and a multitude of methods are currently being used to approximate dose. The choice of a suitable method to determine dose in future studies will depend both on the size and the objectives of the study.
Objective:
Safety concerns deter cycling. The Bicyclists' Injuries and the Cycling Environment (BICE) study quantified the injury risk associated with 14 route types, from off-road paths to major streets. However, when it comes to injury risk, there may be discordance between empirical evidence and perceptions. If so, even if protective infrastructure is built people may not feel safe enough to cycle. This paper reports on the relationship between perceived and observed injury risk.
Methods:
The BICE study is a case-crossover study that recruited 690 injured adult cyclists who visited emergency departments in Toronto and Vancouver. Observed risk was calculated by comparing route types at the injury sites with those at randomly selected control sites along the same route. The perceived risk was the mean response of study participants to the question "How safe do you think this site was for cyclists on that trip?", with responses scored from +1 (very safe) to -1 (very dangerous). Perceived risk scores were only calculated for non-injury control sites, to reduce bias by the injury event.
Results:
The route type with the greatest perceived risk was major streets with shared lanes and no parked cars (mean score = -0.21, 95% confidence interval [CI]: -0.54-0.11), followed by major streets without bicycle infrastructure (-0.07, CI -0.14-0.00). The safest perceived routes were paved multi-use paths (0.66, CI 0.43-0.89), residential streets (0.44, CI 0.37-0.51), bike paths (0.42, CI 0.25-0.60) and residential streets marked as bike routes with traffic calming (0.41, CI 0.32-0.51). Most route types that were perceived as higher risk were found to be so in our injury study; similarly, most route types perceived as safer were also found to be so. Discrepancies were observed for cycle tracks (perceived as less safe than observed) and for multiuse paths (perceived as safer than observed).
Conclusions:
Route choices and decisions to cycle are affected by perceptions of safety, and we found that perceptions usually corresponded with observed safety. However, perceptions about certain separated route types did not align well. Education programs and social media may be ways to ensure that public perceptions of route safety reflect the evidence.
Non-motorized commuting such as, walking and cycling to work has been recognized as essential in attaining sustainability in urban mobility. Owing to this recognition, in recent years there has been a surge of interest among policy makers and practitioners in promoting non-motorized commuting in Ireland. This paper presents an investigative study to explain the non-motorized mode share of commuter journeys in terms of relevant socioeconomic, transportation and household specific factors in five major cities of Ireland. The non-motorized modes were analyzed using the latest available Irish census data (2006). An overall analysis of the entire study region was conducted along with the development of models specific to each city, gender, distance (under and over 5 km) and to the choice between non-motorized modes (walking and cycling) to gain a deeper understanding of the determinants which influence the choice of non-motorized travel mode for commuter journeys. Gender, car ownership and journey distance were revealed by analysis to have the largest effect on the use of non-motorized transport (NMT). Major Irish cities show similar behavior regarding NMT use and nation-wide policy development can be successful, provided some region or city specific differences are incorporated during policy implementation. The developed models are important tools in understanding the effectiveness of the policy interventions in promoting non-motorized travel for utilitarian purposes across the major cities of Ireland.
The primary focus of this study by Sprinkle Consulting Engineers, Inc. is to develop a bicycle-quality, or level-of-service, model for applications in U.S. metropolitan areas. Although there are several model forms being used throughout the United States that attempt to quantify road suitability or the quality of service afforded bicyclists traveling the street and roadway networks of urbanized areas, to date there have been no statistically calibrated models published. The statistically calibrated level-of-service model described here is based on real-time perceptions from bicyclists traveling in actual urban traffic and roadway conditions. The study's participants represented a cross section of age, gender, experience level, and geographic origin of the population of cyclists that use the metropolitan road networks in the United States. The test course is representative of the collector and arterial street systems of North American urban areas. Although further hypothesis testing is being conducted and additional studies are planned to test the need tor disaggregate models for central business district streets with high turnover parking, truck routes, and two-lane high-speed rural high-ways the general bicycle level-of-service model reported here is highly reliable has a high correlation coefficient (R2 = 0.73), and is transferable to the vast majority of United States metropolitan areas. The study reveals that pavement-surface conditions and striping of bicycle lanes are important factors in the quality of service.
A meta-analysis of studies reported outside the United States was performed to evaluate the effects on road safety of converting intersections to roundabouts. Twenty-eight studies that provided 113 estimates of effect were evaluated. State-of-the-art techniques of meta-analysis were applied to synthesize evidence from these evaluation studies. A meta-regression analysis was performed, and the possible presence of publication bias was tested and adjusted using the trim-and-fill method. The results show that roundabouts are associated with a 30% to 50% reduction in the number of injury accidents. Fatal accidents are reduced by 50 % to 70 %. Effects on property damage accidents are highly uncertain, but in three-leg intersections, an increase often will occur. Evidence from the evaluation studies, although highly uncertain, suggests that the effect of roundabouts on injury accidents is greater in four-leg intersections than in three-leg intersections, and it is greater in intersections previously controlled by yield signs than in intersections previously controlled by traffic signals. Few studies have evaluated in detail the effects on safety of design parameters for roundabouts. Findings are inconsistent, but the majority of studies find that small roundabouts (a small diameter of the central traffic island) are safer than large roundabouts (a large diameter of the central traffic island).
The purpose of this Position Stand is to provide guidance to professionals who counsel and prescribe individualized exercise to apparently healthy adults of all ages. These recommendations also may apply to adults with certain chronic diseases or disabilities, when appropriately evaluated and advised by a health professional. This document supersedes the 1998 American College of Sports Medicine (ACSM) Position Stand, "The Recommended Quantity and Quality of Exercise for Developing and Maintaining Cardiorespiratory and Muscular Fitness, and Flexibility in Healthy Adults." The scientific evidence demonstrating the beneficial effects of exercise is indisputable, and the benefits of exercise far outweigh the risks in most adults. A program of regular exercise that includes cardiorespiratory, resistance, flexibility, and neuromotor exercise training beyond activities of daily living to improve and maintain physical fitness and health is essential for most adults. The ACSM recommends that most adults engage in moderate-intensity cardiorespiratory exercise training for ≥30 min·d on ≥5 d·wk for a total of ≥150 min·wk, vigorous-intensity cardiorespiratory exercise training for ≥20 min·d on ≥3 d·wk (≥75 min·wk), or a combination of moderate- and vigorous-intensity exercise to achieve a total energy expenditure of ≥500-1000 MET·min·wk. On 2-3 d·wk, adults should also perform resistance exercises for each of the major muscle groups, and neuromotor exercise involving balance, agility, and coordination. Crucial to maintaining joint range of movement, completing a series of flexibility exercises for each the major muscle-tendon groups (a total of 60 s per exercise) on ≥2 d·wk is recommended. The exercise program should be modified according to an individual's habitual physical activity, physical function, health status, exercise responses, and stated goals. Adults who are unable or unwilling to meet the exercise targets outlined here still can benefit from engaging in amounts of exercise less than recommended. In addition to exercising regularly, there are health benefits in concurrently reducing total time engaged in sedentary pursuits and also by interspersing frequent, short bouts of standing and physical activity between periods of sedentary activity, even in physically active adults. Behaviorally based exercise interventions, the use of behavior change strategies, supervision by an experienced fitness instructor, and exercise that is pleasant and enjoyable can improve adoption and adherence to prescribed exercise programs. Educating adults about and screening for signs and symptoms of CHD and gradual progression of exercise intensity and volume may reduce the risks of exercise. Consultations with a medical professional and diagnostic exercise testing for CHD are useful when clinically indicated but are not recommended for universal screening to enhance the safety of exercise.
The study aim was to identify risk factors for collisions/near-collisions involving on-road commuter cyclists and drivers. A naturalistic cycling study was conducted in Melbourne, Australia, with cyclists wearing helmet-mounted video cameras. Video recordings captured cyclists' perspective of the road and traffic behaviours including head checks, reactions and manoeuvres. The 100-car naturalistic driving study analysis technique was adapted for data analysis and events were classified by severity: collision, near-collision and incident. Participants were adult cyclists and each filmed 12 hours of commuter cycling trips over a 4-week period. In total, 127 hours and 38 minutes were analysed for 13 participants, 54 events were identified: 2 collisions, 6 near-collisions and 46 incidents. Prior to events, 88.9% of cyclists travelled in a safe/legal manner. Sideswipe was the most frequent event type (40.7%). Most events occurred at an intersection/intersection-related location (70.3%). The vehicle driver was judged at fault in the majority of events (87.0%) and no post-event driver reaction was observed (83.3%). Cross tabulations revealed significant associations between event severity and: cyclist reaction, cyclist post-event manoeuvre, pre-event driver behaviour, other vehicle involved, driver reaction, visual obstruction, cyclist head check (left), event type and vehicle location (p<0.05). Frequent head checks suggest cyclists had high situational awareness and their reactive behaviour to driver actions led to successful avoidance of collisions/near-collisions. Strategies to improve driver awareness of on-road cyclists and to indicate early before turning/changing lanes when sharing the roadway with cyclists are discussed. Findings will contribute to the development of effective countermeasures to reduce cyclist trauma.
Background:
There is growing interest in "Health in All Policies" approaches, aiming at promoting health through policies which are under the control of nonhealth sectors. While economic appraisal is an established practice in transport planning, health effects are rarely taken into account. An international project was carried out to develop guidance and tools for practitioners for quantifying the health effects of cycling and walking, supporting their full appraisal.
Development process:
A systematic review of existing approaches was carried out. Then, the products were developed with an international expert panel through an extensive consensus finding process.
Products and applications:
Methodological guidance was developed which addresses the main challenges practitioners encounter in the quantification of health effects from cycling and walking. A "Health Economic Assessment Tool (HEAT) for cycling" was developed which is being used in several countries.
Conclusions:
There is a need for a more consistent approach to the quantification of health benefits from cycling and walking. This project is providing guidance and an illustrative tool for cycling for practical application. Results show that substantial savings can be expected. Such tools illustrate the importance of considering health in transport policy and infrastructure planning, putting "Health in All Policies" into practice.
Bicycling has the potential to improve fitness, diminish obesity, and reduce noise, air pollution, and greenhouse gases associated with travel. However, bicyclists incur a higher risk of injuries requiring hospitalization than motor vehicle occupants. Therefore, understanding ways of making bicycling safer and increasing rates of bicycling are important to improving population health. There is a growing body of research examining transportation infrastructure and the risk of injury to bicyclists.
We reviewed studies of the impact of transportation infrastructure on bicyclist safety. The results were tabulated within two categories of infrastructure, namely that at intersections (e.g. roundabouts, traffic lights) or between intersections on "straightaways" (e.g. bike lanes or paths). To assess safety, studies examining the following outcomes were included: injuries; injury severity; and crashes (collisions and/or falls).
The literature to date on transportation infrastructure and cyclist safety is limited by the incomplete range of facilities studied and difficulties in controlling for exposure to risk. However, evidence from the 23 papers reviewed (eight that examined intersections and 15 that examined straightaways) suggests that infrastructure influences injury and crash risk. Intersection studies focused mainly on roundabouts. They found that multi-lane roundabouts can significantly increase risk to bicyclists unless a separated cycle track is included in the design. Studies of straightaways grouped facilities into few categories, such that facilities with potentially different risks may have been classified within a single category. Results to date suggest that sidewalks and multi-use trails pose the highest risk, major roads are more hazardous than minor roads, and the presence of bicycle facilities (e.g. on-road bike routes, on-road marked bike lanes, and off-road bike paths) was associated with the lowest risk.
Evidence is beginning to accumulate that purpose-built bicycle-specific facilities reduce crashes and injuries among cyclists, providing the basis for initial transportation engineering guidelines for cyclist safety. Street lighting, paved surfaces, and low-angled grades are additional factors that appear to improve cyclist safety. Future research examining a greater variety of infrastructure would allow development of more detailed guidelines.
The classic conception of stress involves undifferentiated negative affect and corresponding biological reactivity. The present study hypothesized a new conception, disaggregating stress into emotion-specific, contrasting patterns of biological response. Specifically, it hypothesized contrasting patterns for indignation (comprised of anger and disgust) versus fear. Moreover, it hypothesized that facial expressions of these emotions would signal corresponding biological stress responses.
Ninety-two adults engaged in annoyingly difficult stress-challenge tasks, during which cardiovascular responses, hypothalamic-pituitary-adrenocortical (HPA) axis responses (i.e., cortisol), emotional expressions (i.e., facial muscle movements), and subjective emotional experience were assessed.
Pronounced individual differences emerged in specific emotional responses to the stressors. Analyses of facial expressions revealed that the more fear individuals displayed in response to the stressors, the higher their cardiovascular and cortisol responses to stress. By contrast, the more indignation individuals displayed in response to the same stressors the lower their cortisol levels and cardiovascular responses.
Facial expressions of emotion signal biological responses to stress. Fear expressions signal elevated cortisol and cardiovascular reactivity; indignation signals attenuated cortisol and cardiovascular reactivity, patterns that implicate individual differences in stress appraisals. Rather than conceptualizing stress as generalized negative affect, studies can be informed by this emotion-specific approach to stress responses.
The Actiheart (Mini Mitter, Sunriver, OR, USA) uses heart rate (HR) and activity data to predict activity energy expenditure (AEE). Currently, the Actiheart has only been tested during laboratory conditions. Therefore, the objective of this study was to validate the Actiheart prediction method against indirect calorimetry during a wide range of activities in a field setting.
Forty-eight participants (age: 35+/-11.4 years) were recruited for the study. Eighteen activities were split into three routines of six activities and each routine was performed by 20 participants. During each routine, the participants wore an Actiheart and simultaneously, AEE was measured with a Cosmed K4b(2) portable metabolic system. The manufacturer's HR algorithm, activity algorithm, and combined activity and HR algorithm were used to estimate AEE.
The mean error (and 95% prediction intervals) for the combined activity and HR algorithm, HR algorithm, and activity algorithm versus the Cosmed K4b(2) were 0.02 kJ kg(-1) min(-1) (-0.17, 0.22 kJ kg(-1) min(-1)), -0.03 kJ kg(-1) min(-1) (-0.24, 0.18 kJ kg(-1) min(-1)), and 0.14 kJ kg(-1) min(-1) (-0.12, 0.40 kJ kg(-1) min(-1)), respectively.
The Actiheart combined activity and HR algorithm and HR algorithm provide similar estimates of AEE on both a group and individual basis.
Converting an intersection into a roundabout improves motor vehicle safety, but a similar safety effect is not found for car-bicycle collisions. Very little is known about the reasons behind these collisions. In this study a first step towards an understanding of the reasons behind these collisions is taken. The study focuses on cyclists' perceived risk in specific situations, factors influencing the perception of risk and cyclists' knowledge about traffic rules regulating the interaction between road users in roundabouts. One thousand and nineteen cyclists aged 18-85 participated in the study. Data were collected using structured interviews conducted in five Danish roundabouts. Underestimation of risk and lack of knowledge about relevant traffic rules may contribute to car-bicycle collisions in roundabouts. Cyclists prefer road designs with a clear regulation of road user behaviour. A need to increase knowledge about traffic rules regulating road user behaviour in roundabouts is identified.
The combination of heart rate (HR) monitoring and movement registration may improve measurement precision of physical activity energy expenditure (PAEE). Previous attempts have used either regression methods, which do not take full advantage of synchronized data, or have not used movement data quantitatively. The objective of the study was to assess the precision of branched model estimates of PAEE by utilizing either individual calibration (IC) of HR and accelerometry or corresponding mean group calibration (GC) equations. In 12 men (20.6-25.2 kg/m2), IC and GC equations for physical activity intensity (PAI) were derived during treadmill walking and running for both HR (Polar) and hipacceleration [Computer Science and Applications (CSA)]. HR and CSA were recorded minute by minute during 22 h of whole body calorimetry and converted into PAI in four different weightings (P1-4) of the HR vs. the CSA (1-P1-4) relationships: if CSA > x, we used the P1 weighting if HR > y, otherwise P2. Similarly, if CSA < or = x, we used P3 if HR > z, otherwise P4. PAEE was calculated for a 12.5-h nonsleeping period as the time integral of PAI. A priori, we assumed P1 = 1, P2 = P3 = 0.5, P4 = 0, x = 5 counts/min, y = walking/running transition HR, and z = flex HR. These parameters were also estimated post hoc. Means +/- SD estimation errors of a priori models were -4.4 +/- 29 and 3.5 +/- 20% for IC and GC, respectively. Corresponding post hoc model errors were -1.5 +/- 13 and 0.1 +/- 9.8%, respectively. All branched models had lower errors (P < or = 0.035) than single-measure estimates of CSA (less than or equal to -45%) and HR (> or =39%), as well as their nonbranched combination (> or =25.7%). In conclusion, combining HR and CSA by branched modeling improves estimates of PAEE. IC may be less crucial with this modeling technique.
Background
There is growing interest in “Health in All Policies” approaches, aiming at promoting health through policies which are under the control of nonhealth sectors. While economic appraisal is an established practice in transport planning, health effects are rarely taken into account. An international project was carried out to develop guidance and tools for practitioners for quantifying the health effects of cycling and walking, supporting their full appraisal.
Development Process
A systematic review of existing approaches was carried out. Then, the products were developed with an international expert panel through an extensive consensus finding process.
Products and Applications
Methodological guidance was developed which addresses the main challenges practitioners encounter in the quantification of health effects from cycling and walking. A “Health Economic Assessment Tool (HEAT) for cycling” was developed which is being used in several countries.
Conclusions
There is a need for a more consistent approach to the quantification of health benefits from cycling and walking. This project is providing guidance and an illustrative tool for cycling for practical application. Results show that substantial savings can be expected. Such tools illustrate the importance of considering health in transport policy and infrastructure planning, putting “Health in All Policies” into practice.
Clay Reynolds is Professor of Arts & Humanities and Director of Creative Writing at the University of Texas at Dallas. A writer and scholar, his most recent work of fiction is Sandhill County Lines.
Plots, probability plots and regression tests tests using moments other tests for univariate normality goodness of fit tests testing for outliers in univariate samples power comparisons for univariate tests for normality testing for normalitywith censored data assessing multivariate normality testing for multivariate outliers testing for normal mixtures robust methods computational methods and issues. Appendices: data sets used in examples critical values for tests.
The authors provide a cautionary note on reporting accurate eta-squared values from multifactor analysis of variance (ANOVA) designs. They reinforce the distinction between classical and partial eta-squared as measures of strength of association. They provide examples from articles published in premier psychology journals in which the authors erroneously reported partial eta-squared values as representing classical etasquared values. Finally, they discuss broader impacts of inaccurately reported etasquared values for theory development, meta-analytic reviews, and intervention programs.
The effects of listening to music on cycling behaviour were evaluated. Twenty-five participants completed a track on a bicycle while listening to music with two standard earbuds, with one earbud, and with two in-earbuds. Conditions with high tempo music and loud volume were also included in the experiment, as were two mobile phone conditions, one in which participants operated the phone hand held and one handsfree condition.Cycle speed was not affected by listening to music, but was reduced in the telephone conditions. In general the response to auditory signals worsened when participants listened to music, in particular when listening with in-earbuds loud auditory stop signals were missed in 68% of the cases. However, when listening with only one standard earbud performance was not affected. In the conditions when participants listened to high volume and to high tempo music, the auditory stop signal was also heard in significantly fewer cases. Completing a task on the mobile phone, using both handheld and handsfree sets, resulted in increased response time to an auditory stop signal and also reduced overall auditory perception. Furthermore, handsfree operation only had minor advantages opposed to hand held operation, with only response time to an auditory stop signal resulting in faster performance. This is likely to be related to the fact that both hands could be used for braking.It is concluded that listening to music worsens auditory perception, in particular if in-earbuds are used. Furthermore, both handheld and handsfree operation of mobile phones has a negative effect on perception, potentially forming a threat to cyclist traffic safety.
Bicycles offer a promising transportation alternative to private motor vehicles, especially in areas with congestion, poor air quality, and high fuel prices. The study on which this paper is based sought rational methods for determining the most efficient use of the available funds to improve bicycle transportation. A bicycle network analysis tool was developed to assess the networkwide level of service offered to bicyclists in a study area. The tool uses route length and measures of perceived safety to quantify the bicycle friendliness of a street network. The tool can be used to compare networks and assist with the selection of locations for bicycle facility improvements.
This article offers a practical guide to goodness-of-fit tests using statistics based on the empirical distribution function (EDF). Five of the leading statistics are examined—those often labelled D, W , V, U , A —and three important situations: where the hypothesized distribution F(x) is completely specified and where F(x) represents the normal or exponential distribution with one or more parameters to be estimated from the data. EDF statistics are easily calculated, and the tests require only one line of significance points for each situation. They are also shown to be competitive in terms of power.
Increasing regular physical activity is a key public health goal. One strategy is to change the physical environment to encourage walking and cycling, requiring partnerships with the transport and urban planning sectors. Economic evaluation is an important factor in the decision to fund any new transport scheme, but techniques for assessing the economic value of the health benefits of cycling and walking have tended to be less sophisticated than the approaches used for assessing other benefits. This study aimed to produce a practical tool for estimating the economic impact of reduced mortality due to increased cycling. The tool was intended to be transparent, easy to use, reliable, and based on conservative assumptions and default values, which can be used in the absence of local data. It addressed the question: For a given volume of cycling within a defined population, what is the economic value of the health benefits? The authors used published estimates of relative risk of all-cause mortality among regular cyclists and applied these to levels of cycling defined by the user to produce an estimate of the number of deaths potentially averted because of regular cycling. The tool then calculates the economic value of the deaths averted using the "value of a statistical life." The outputs of the tool support decision making on cycle infrastructure or policies, or can be used as part of an integrated economic appraisal. The tool's unique contribution is that it takes a public health approach to a transport problem, addresses it in epidemiologic terms, and places the results back into the transport context. Examples of its use include its adoption by the English and Swedish departments of transport as the recommended methodologic approach for estimating the health impact of walking and cycling.
The levels of bicycling in the United States, particularly for nonrecreation purposes and among adults, are low. Only about 1% of the trips that people make in the United States are on bicycles, and less than 5% of trips under 1/2 mi are made on bicycles. Factors influencing the rates of cycling include demographics and environmental factors. Environmental factors can be measured both objectively (e.g., number of miles of bike lanes, average temperature, and street connectivity) and subjectively (e.g., people's ratings or perceptions of the bicycling environment). People's attitudes about travel and mobility likely play a role. This paper uses the results from a random phone survey of adults in the Portland, Oregon, region to explore the relationships between levels of cycling and demographics, objective environmental factors, perceptions of the environment, and attitudes. The survey revealed several significant differences, although additional analysis is necessary. Objective measures of proximity to off-street trails and bike lanes was not associated with higher levels of cycling. However, positive perceptions of the availability of bike lanes was associated with more cycling and the desire to cycle more. Higher levels of street connectivity were associated with more cycling for utilitarian trips.
In a survey of 1,402 current and potential cyclists in Metro Vancouver, 73 motivators and deterrents of cycling were evaluated.
The top motivators, consistent among regular, frequent, occasional and potential cyclists, were: routes away from traffic
noise and pollution; routes with beautiful scenery; and paths separated from traffic.In factor analysis, the 73 survey items
were grouped into 15 factors. The following factors had the most influence on likelihood of cycling: safety; ease of cycling;
weather conditions; route conditions; and interactions with motor vehicles. These results indicate the importance of the location
and design of bicycle routes to promote cycling.
KeywordsBicycle-Survey-Infrastructure-Influence-Non-motorized transport
In the present study, the frequency, determinants and consequences of three relevant emotions in traffic were investigated. Based on appraisal theory, it was predicted that the combination of three appraisal components (goal congruence, blame and threat) affects the occurrence of anger, anxiety and happiness. Participants (n = 44) filled in a questionnaire containing background and personality variables, and performed a test drive in an instrumented car. During the drive, speed and heart rate were registered and the traffic environment was recorded on video. Participants verbally reported scores for emotions and perceived risk. The most frequently occurring emotion was anxiety, followed by anger and happiness. Emotions while driving were related to emotional traits. Emotions while driving were also related to traffic events: anger and anxiety were both associated with goal incongruent events, and happiness with goal congruent events. Anger was mostly associated with other-blame and anxiety with situation-blame. Anger was mostly associated with events affecting impeded progress, and anxiety with events affecting safety. Anxiety, but not anger or happiness, was associated with increased perceived risk and with increased heart rate. Participants who reported anger drove faster and exceeded the speed limit more often on a 100 km/road section than participants who did not report anger. These and other results are discussed in terms of appraisal theory and state-trait differences in emotion.
We report two experiments designed to investigate the potential use of vibrotactile warning signals to present spatial information to car drivers. Participants performed an attention-demanding rapid serial visual presentation (RSVP) monitoring task. Meanwhile, whenever they felt a vibrotactile stimulus presented on either their front or back, they had to check the front and the rearview mirror for the rapid approach of a car, and brake or accelerate accordingly. We investigated whether speeded responses to potential emergency driving situations could be facilitated by the presentation of spatially-predictive (80% valid; Experiment 1) or spatially-nonpredictive (50% valid; Experiment 2) vibrotactile cues. Participants responded significantly more rapidly following both spatially-predictive and spatially-nonpredictive vibrotactile cues from the same rather than the opposite direction as the critical driving events. These results highlight the potential utility of vibrotactile warning signals in automobile interface design for directing a driver’s visual attention to time-critical events or information.
The study presents cost–benefit analyses of walking and cycling track networks in three Norwegian cities. The cost–benefit analyses take into account the benefit of reduced insecurity and the health benefits of the improved fitness the use of non-motorized transport provides. In addition to reductions in health costs, the analyses also take into account that a change from travel by car to cycling or walking means reduced external costs (e.g. air pollution and noise) from motorized traffic and reduced parking costs. The benefits of investments in cycle networks are estimated to be at least 4–5 times the costs. Such investments are thus more beneficial to society than other transport investments.The results of such complete cost–benefit analyses make it possible to calculate the benefits to society that are not realized because motorized traffic prevents people from bicycling or walking as much as they otherwise would prefer. These “barrier costs” attributable to motorized traffic are estimated to be of at least the same magnitude as air pollution costs and more than double the noise costs. Barrier costs should therefore be taken into account in the same way as other external costs, when the issue is to determine the proper level of car taxes or to evaluate different kinds of restrictions on car use.
A vibrotactile display, consisting of eight vibrating elements or tactors mounted in a driver’s seat, was tested in a driving simulator. Participants drove with visual, tactile and multimodal navigation displays through a built-up area. Workload and the reaction time to navigation messages were measured for normal and high workload conditions. The results demonstrated that the tactile navigation display reduces the driver’s workload compared to the visual display, particularly in the high workload group. The fastest reaction was found with the multimodal display. It was concluded that this study quantitatively supports the claims that a localised vibration or tap is an intuitive way to present direction information, and that employing the tactile channel may release other heavily loaded sensory channels, therefore potentially providing a major safety enhancement.
We reviewed published and unpublished studies that presented the findings of an economic valuation of an aspect of transport infrastructure or policy, and included data on walking and/or cycling and health effects in the valuation. We included 16 papers, of which three were classified as ‘high; six as ‘moderate’ and seven as ‘low’ quality. There is a wide variation in the approaches taken for including the health effects of physical activity in economic analyses of transport projects. This is not helped by a lack of transparency of methods in many studies. A more standardised approach is called for, including a clearer description of the applied methods and assumptions taken.
Background:
Wearable monitors are increasingly being used to objectively monitor physical activity in research studies within the field of exercise science. Calibration and validation of these devices are vital to obtaining accurate data. This article is aimed primarily at the physical activity measurement specialist, although the end user who is conducting studies with these devices also may benefit from knowing about this topic.
Best practices:
Initially, wearable physical activity monitors should undergo unit calibration to ensure interinstrument reliability. The next step is to simultaneously collect both raw signal data (e.g., acceleration) from the wearable monitors and rates of energy expenditure, so that algorithms can be developed to convert the direct signals into energy expenditure. This process should use multiple wearable monitors and a large and diverse subject group and should include a wide range of physical activities commonly performed in daily life (from sedentary to vigorous).
Future directions:
New methods of calibration now use "pattern recognition" approaches to train the algorithms on various activities, and they provide estimates of energy expenditure that are much better than those previously available with the single-regression approach. Once a method of predicting energy expenditure has been established, the next step is to examine its predictive accuracy by cross-validating it in other populations. In this article, we attempt to summarize the best practices for calibration and validation of wearable physical activity monitors. Finally, we conclude with some ideas for future research ideas that will move the field of physical activity measurement forward.
Following decades of controversy and uncertainty, there is now sufficient empirical basis for asserting the existence of a limited set of autonomic differences among emotions. Findings of autonomic distinctions among emotions-derived from the work of the author and his colleagues using two methods of emotion elicitation are reviewed. For five of these autonomic distinctions, convergent findings from the work of other investigators using the same and other elicitation methods are presented. © 1992, Association for Psychological Science. All rights reserved.
To provide evidence about the types of transportation infrastructure that support bicycling.
Population-based survey with pictures to depict 16 route types.
Metro Vancouver, Canada.
1402 adult current and potential cyclists, i.e., the "near market" for cycling (representing 31% of the population).
Preference scores for each infrastructure type (scale from -1, very unlikely to use, to +1, very likely to use); current frequency of use of each infrastructure type (mean number of times/y).
Descriptive statistics across demographic segments; multiple linear regression.
Most respondents were likely or very likely to choose to cycle on the following broad route categories: off-street paths (71%-85% of respondents); physically separated routes next to major roads (71%); and residential routes (48%-65%). Rural roads (21%-49%) and routes on major streets (16%-52%) were least likely to be chosen. Within the broad categories, routes with traffic calming, bike lanes, paved surfaces, and no on-street parking were preferred, resulting in increases in likelihood of choosing the route from 12% to 37%. Findings indicate a marked disparity between preferred cycling infrastructure and the route types that were currently available and commonly used.
This study provides evidence for urban planners about bicycling infrastructure designs that could lead to an increase in active transportation.
(1)Every type of exercise is in a sense a unique situation. However, all forms of muscular work do increase the metabolic rate and therefore it is of particular interest to analyse the involvement of the oxygen transport system. The oxygen uptake gives an accurate measure of the aerobic power, and it is highly related to the cardiac output. The VO2 max is under standardized conditions a highly reproducible characteristic of the individual's aerobic fitness. It is however, subject to variations under certain conditions (i.e., after prolonged inactivity, after training, as a consequence of cardiac diseases). The main factor behind such variations in VO2 max is proportional changes in the stroke volume. Therefore a recording of the heart rate during exercise at a given oxygen uptake will reflect these variations in longitudinal studies. Generally speaking, a high heart rate is usually associated with a low stroke volume. However, from this information it is not possible to tell whether this (poor) exercise response was caused by genetic factors, lack of training, impaired heart function, or other factors. (2) Data have been presented suggesting that the maximal transport of oxygen (cardiac output X oxygen content of arterial blood) is limited by the central circulation rather than by the tissues' ability to utilize the oxygen. (3) A multi-stage exercise test on a treadmill or bicycle ergometer will provide a measurement of the rate of work an individual is able to tolerate without symptoms or electro-cardiographic abnormalities...
A transportation mode choice analysis is performed that examines behavioral responses to perceived risk in the choice of mode for daily commute trips. This methodology provides a technique for examining, by means of disaggregate individual level data, risk-compensating effects in transportation systems. Various measures of perceived risk are examined for explaining modal choice. Other studies have described how safety regulations have resulted in increases in "driving intensity." This study defines one component of driving intensity to be the increased probability of commuting by automobile. The results show that modal shifts occur when risk perceptions for a given mode are reduced. To demonstrate potential risk-compensating effects within the transportation system, an estimate of changes in accident fatalities due to commuting is derived using rough estimates of fatalities per person-mile travelled. It is shown that a given change in the perceived risk of commuting by automobile results in a less than proportionate change in net commuting fatalities. The relative magnitude is dependent on how objective reductions in risk translate into perceived reductions in risk. This study also shows that perceived safety improvements in bicycle transportation have an aggregate elasticity value that is greater than one. This means that bicycle safety improvements attract proportionately more people to bicycle commuting (i.e. a 10% increase in safety results in a greater than 10% increase in the share of people bicycle commuting).
This paper presents a risk index model that can be used for assessing the safety effect of countermeasures. The model estimates risk in a multiplicative way, which makes it possible to analyze the impact of different factors separately. Expert judgments are incorporated through a Bayesian error model. The variance of the risk estimate is determined by Monte-Carlo simulation. The model was applied to assess the safety effect of a new design of a bicycle crossing. The intent was to gain safety by raising the crossings to reduce vehicle speeds and by making the crossings more visible by painting them in a bright color. Before the implementations, bicyclists were riding on bicycle crossings of conventional Swedish type, i.e. similar to crosswalks but delineated by white squares rather than solid lines or zebra markings. Automobile speeds were reduced as anticipated. However, it seems as if the positive effect of this was more or less canceled out by increased bicycle speeds. The safety per bicyclist was still improved by approximately 20%. This improvement was primarily caused by an increase in bicycle flow, since the data show that more bicyclists at a given location seem to benefit their safety. The increase in bicycle flow was probably caused by the new layout of the crossings since bicyclists perceived them as safer and causing less delay. Some future development work is suggested. Pros and cons with the used methodology are discussed. The most crucial parameter to be added is probably a model describing the interaction between motorists and bicyclists, for example, how risk is influenced by the lateral position of the bicyclist in relation to the motorist. It is concluded that the interaction seems to be optimal when both groups share the roadway.
The classic conception of stress involves undifferentiated negative affect and corresponding biological reactivity. The present study hypothesized a new conception that disaggregates stress into emotion-specific, contrasting patterns of biological response.
Ninety-two healthy adults engaged in stress-challenge tasks, during which cardiovascular responses, hypothalamic-pituitary-adrenocortical (HPA) axis responses (i.e., cortisol), emotional expressions (i.e., facial muscle movements), and subjective emotional experience (self-reported) were assessed.
Pronounced individual differences emerged in specific emotional responses to the stressors. Analyses of facial expressions revealed that the more fear individuals displayed in response to the stressors, the higher their cardiovascular and cortisol responses to stress. By contrast, the more anger and disgust (indignation) individuals displayed in response to the same stressors, the lower their cortisol levels and cardiovascular responses. Individual differences in optimistic appraisals appeared to mediate these correlated patterns.
Facial expressions of emotion signal biological responses to stress. Fear expressions signal elevated cortisol and cardiovascular reactivity; anger and disgust signal attenuated cortisol and cardiovascular reactivity, patterns that implicate individual differences in stress appraisals. Rather than conceptualizing stress as generalized negative affect, studies can be informed by this emotion-specific approach to stress responses.
Perceived cycling risk and route acceptability to potential users are obstacles to policy support for cycling and a better understanding of these issues will assist planners and decision makers. Two models of perceived risk, based on non-linear least squares, and a model of acceptability, based on the logit model, have been estimated for whole journeys based on responses from a sample of 144 commuters to video clips of routes and junctions.
The risk models quantify the effect of motor traffic volumes, demonstrate that roundabouts add more to perceived risk than traffic signal controlled junctions and show that right turn manoeuvres increase perceived risk. Facilities for bicycle traffic along motor trafficked routes and at junctions are shown to have little effect on perceived risk and this brings into question the value of such facilities in promoting bicycle use. These models would assist in specifying infrastructure improvements, the recommending of least risk advisory routes and assessing accessibility for bicycle traffic.
The acceptability model confirms the effect of reduced perceived risk in traffic free conditions and the effects of signal controlled junctions and right turns. The acceptability models, which may be used at an area wide level, would assist in assessing the potential demand for cycling and in target setting.
during Gap course. Fig. 5. Distribution of median heart rates for each course type and difficulty level (L1, L2, L3) in the fully controlled experiment. Fig. 6. Frequency distribution of reported risk ratings Selecting and effectively using a heart rate monitor
- E B Subject
Fig. 4. Evolution of heart rate for subject, E.B., during Gap course. Fig. 5. Distribution of median heart rates for each course type and difficulty level (L1, L2, L3) in the fully controlled experiment. Fig. 6. Frequency distribution of reported risk ratings. References ACSM (2011). Selecting and effectively using a heart rate monitor [Online]. Available: <http://www.acsm.org/docs/brochures/selecting-and-effectively-using-a-heart-rate-monitor.pdf>.
Attitudes of cyclists and car commuters to cycling in Dublin
- O Keegan
- J Galbraith
Keegan, O., & Galbraith, J. (2005). Attitudes of cyclists and car commuters to cycling in Dublin. In: Paper presented at Velocity Conference, Dublin.
Kirk, R. E. (1995). Experimental design: Procedures for the behavioral sciences. London: Brooks/Cole Publishing Company.