Individual Cyclists Research Articles

Wider view over bicycle crashes: Complementing and extending bicycle crash statistics in urban areas using surveys

Introduction: In pursuit of sustainability goals, many cities are introducing measures to increase the usage of bicycles as a means of transportation. City planners aim to ensure that this increase does not lead to an increase in crashes, but must make corresponding infrastructure decisions with limited information. Sufficient data to perform a statistical analysis of location-specific crash frequencies is rarely available. For example, only approximately 10% of all bicycle crashes are reported to the police (Shinar et al., 2018). Therefore, urban planners often rely on expert opinion, which may lead to suboptimal prioritization and realization of infrastructure improvements. Method: This paper demonstrates how surveys on bicycle crashes can be used to aid urban planners in making infrastructure decisions. In addition to confirming the location and characteristics of reported crashes, surveys can uncover characteristics of crashes that are not reported to the police, situations in which a crash almost occurred, and locations perceived by cyclists to be dangerous. Surveys also allow urban planners to investigate non-infrastructure related causes of crashes, such as the frequency with which individual cyclists use other modes of transportation. Practical Applications: The usefulness of surveys in the determination of urban cycling safety is demonstrated in this paper through analysis of survey results from the city of Zurich in 2018.

Exploring Microscopic Characteristics of Bicycle Riders’ following Behaviors in a Single-File Movement

Cycling can bring a wide range of social, economic, and health benefits to individuals and communities. The safety and efficiency of bicycle facilities can be significantly impacted by the interactions among riders. This study aims to examine the microscopic characteristics of how cyclists interact with each other when they are in a single file movement based on the trajectory data collected from an experiment. Reaction delay was obtained by optimizing the correlation between relative speed and acceleration curves for individual cyclists and it was found that even for a given cyclist, this characteristic time delay could vary considerably, and be situation-dependent. Furthermore, it was found that the distribution of reaction delay, which has an average (±SD) of 0.66 s (±0.33 s), followed a log-normal distribution. The strong correlation observed between relative speed and time-delayed acceleration resembles the behavior observed in car-following situations, highlighting that relative speed is an essential factor influencing the acceleration behavior of cyclists. Multiple linear regression models were used to understand the association between acceleration and other key microscopic variables, e.g., spacing and relative speed, which are commonly used in microscopic behavior models. While the spacing between cyclists was found to have a significant impact on acceleration behavior, its effect was not as significant as that of relative speed. The outcomes of this study provide valuable insights into the cyclists’ behavior and can aid in the development of microscopic simulation models.

Aerodynamic impact of cycling postures on drafting in single paceline configurations

This paper presents finite-volume-based scale-adaptive simulations of single paceline configurations up to eight cyclists for three different postures. In cycling, drag reduction by drafting in pacelines is a key strategy to limit energy expenditure. The drag reductions of individual cyclists and of the paceline as a whole are determined by several factors, including cycling posture. To the best of our knowledge, a systematic study on the effect of cyclist posture on the drag in single pacelines has not yet been published in the scientific literature. In this study, drag reduction and flow field data were computed while validation was performed by wind tunnel measurements. The three investigated postures concern a road race dropped posture with either a large or small sagittal torso angle and a time trial posture. For the considered pacelines in which all cyclists have the same posture, the drag of a cyclist could be reduced by changing either the posture, or the position, or both. Changing posture can yield a maximum drag reduction of about 15% for the leading cyclist. The position in the paceline with minimum drag was the one but last, independent of the investigated cycling postures. For the pacelines containing eight cyclists, maximum drag reductions up to 63% were found. The largest drag reduction was 68%, obtained by riding in penultimate position in an eight cyclist paceline in dropped position with a small sagittal torso angle.

Group cycling safety behaviours: A systematic review

BackgroundThe popularity of cycling in a group is longstanding and increasing. Compared to riding as an individual, many cyclists feel safer when riding in a group as they have better personal security, potential support in case of mishaps, safer wayfinding and are more visible to other road users. However, further to the safety challenges shared with individual cyclists, group cyclist safety is impacted by rider proximity, the larger space taken up on roadways, potentially higher speeds, and social norms that could increase risky behaviours. Despite these unique safety considerations, the practice of cycling in groups has received little academic attention and group cyclist safety behaviours have not been analysed by road safety researchers. ObjectiveTo identify, describe, categorise and conceptualise within a teamwork framework, safety related behaviours of groups of cyclists as mentioned in academic literature. MethodsThree academic databases (Google Scholar, Proquest, and Scopus) were searched for peer reviewed literature that mentioned safe or risky behaviours of groups of cyclists. A total of 32 papers met the inclusion criteria. Relevant group cyclist behaviours were described and categorised using a conceptual teamwork framework. ResultsGroup cyclists’ safety behaviours are governed by a comprehensive but informal and adaptable set of rules. These rules are safety critical and are often strictly controlled within groups. Many groups of cyclists may ride in a safer manner than individual cyclists due to teamwork factors, particularly shared mental models, team orientation, and adaptability. ConclusionGroup cyclists take safety seriously. Teamwork factors may make behavioural interventions to decrease risky behaviours easier to implement with group cyclists compared to individual cyclists. Investigation of group cycling safety behaviours may inform safe system interventions to increase road safety.

Differences in execution and perception of training sessions as experienced by (semi-) professional cyclists and their coach

ABSTRACT This study aimed to investigate whether (semi-)professional cyclists’ execution of a training programme differs from the coach’s designed training programme. Also, the study sought to ascertain, in instances where the training sessions were indeed executed as designed by the coach, whether the perception of the cyclists differed from the intention of the coach. This study highlights the differences between the coach and the individual cyclist. In total, 747 training sessions were collected from 11 (semi-)professional cyclists. Rating of Perceived Exertion (RPE) and session Rating of Perceived Exertion (sRPE) were compared with intended RPE (iRPE) and intended sRPE (isRPE), planned by the coach. Pearson’s correlation, regression coefficients and Typical Error of Estimate (TEE) were used to identify differences between the executed and planned training sessions. Moderate to large TEEs were noted between executed and intended sRPE, which indicates that cyclists do not always execute the training programme planned by the coach. Furthermore, when the training was executed as planned by the coach, very large correlations but moderate to very large TEEs were noted between cyclists’ (s)RPE and the coach’s i(s)RPE, with unique individual regression coefficients. This indicates that the relationship between RPE and iRPE is unique to each cyclist. Both the different execution and perception of the training programme by the individual cyclists could cause an impaired training adaptation. Therefore, the coach must pay attention to the perception of training sessions by the individual cyclist. Improved individual management of training load could result in the optimisation of the proposed training programme.

Effects of vehicle emissions on the PM2.5 dispersion and intake fraction in urban street canyons

Vehicle emissions are the primary source of particulate matter 2.5 (PM2.5) emissions, and exposure to traffic-related air pollution can harm human health. The significance of source–exposure relationship study in a street canyon scale is emphasized in this paper. This study predicts and compares the distribution of PM2.5 and its intake fraction (IF) for individual pedestrians, cyclists, and passengers under different traffic volumes and in different road lanes in one street. PM2.5 concentrations decrease with increasing building height. For the same lane and street, the average PM2.5 concentration during the on-peak period for the number of motor vehicles is approximately 2.2–2.5 and 69.5–77.1 times higher than those during the flat peak and low ebb periods, respectively. Moreover, the average PM2.5 concentration at a wind velocity of 1 m/s is approximately 1.6–2.0 and 6.2–9.8 times higher than those at wind velocities of 3 and 6 m/s, respectively, for the same lane and street. Over a 24-h period in Weijin Road–South Gate Avenue, the maximal individual IF of PM2.5 is (6.79 ± 6.96) × 10−10 for adults on the sidewalk during the on-peak period of traffic volume and (4.11 ± 4.25) × 10−10 for children on the sidewalk during the low ebb period of traffic volume. The IFs of PM2.5 for adults are approximately 1.6 times higher than those for children for the same lane and traffic volume. For each ton of PM2.5 emissions from vehicles on the peak, 0.11, 0.33, and 0.68 mg of PM2.5 are inhaled by adults on the motorway, non-motorway, and sidewalk, respectively, in Weijin Road–South Gate Avenue. The corresponding values for children are 0.07, 0.22, and 0.40 mg of PM2.5, respectively. Our application focus on intake fraction a small street scale, which can be of fundamental interest for further research.

Single-bicycle crashes: An in-depth analysis of self-reported crashes and estimation of attributable hospital cost

Cyclists’ awareness of their risk of single-bicycle crashes is limited. Thus, knowledge of the most common contributory factors of single-bicycle crashes is required. Similarly, single-bicycle crashes and their costs to society are under-recognized by the public. The aim of this study was to conduct an analysis of single-bicycle crashes occurring in a cohort of cyclists in Denmark and supplement it with estimation of some attributable costs of single-bicycle crashes among all injured cyclists during one year treated in a hospital or emergency room in Denmark. We conducted a one-year follow-up of 6,793 active cyclists (mean age: 45.8 years) encountering 349 single-bicycle crashes (single-bicycle crash rate: 55 per 1,000 person-years). An in-depth analysis of the crashes suggested that daily winter road maintenance is crucial in colder climates and that the current cyclist infrastructure design gives rise to many single-bicycle crashes. Further analysis of the co-occurrence of the factors contributing to the crashes indicated that when the weather is warmer, the factors pertaining to the individual cyclist (and not the road authorities) dominate. The risk of sustaining a more severe injury (i.e. other than light bruises) once in a single-bicycle crash was 18 %. However, for cyclists above 50 years, this risk doubled compared with their younger counterparts, wholly due to a 4.7 times higher risk during the warm season. Among cyclists treated in hospital or emergency room, we estimated the attributable hospital cost of single-bicycle crashes at €1,701 and the attributable cost of municipality care at €417 in the first year after the injury (2019 prices). In cyclists aged 18–60 years and treated in hospital or emergency room, the estimated attributable risk of sickness benefit was 5.2 percentage points in the first year after the injury. We concluded that to increase cyclist safety, the road authorities should improve winter road maintenance and redesign cyclist infrastructure.

State transitions among groups of cyclists in cycling points races

ABSTRACT This study analyzed the global state of groups formed by cyclists competing in three different points races and considered the behaviour of individual cyclists in those races. We measured the time difference between the front cyclist and the other cyclists when they crossed the centrelines of home and back straights in order to quantify the global configuration of cyclists in terms of their density and features of states, extracted using principal components analysis (PCA). We examined whether the group separation and group density that characterize the cycling race can be extracted by PCA. We interpreted the PCA results to explain the separation and density of the group using the first and second principal components. Then, we defined the state of configuration of the cyclists in each lap in the plane of the first and second principal components. Subsequently, the state transition probabilities were obtained. States 1, 2, 3, and 4 corresponded to the third, second, first, and fourth quadrants, respectively. State 1 represented a state comprising one dense group, state 2 represented one stretched group, state 3 represented a divided group, and state 4 represented an escape group far from a single dense group. Highlights An approach to understand the collective behaviour of cycling points races through principal component analysis was effective for quantifying the configuration of the cyclists. Principal component analysis of the global configuration of the cyclists in the points races revealed the fission-fusion dynamics was characterized by two components. The density of a group and number of groups, and transitions among four states was defined by these two components. State transition probabilities indicate that the group separation states were more frequent in the latter half of the sprint interval, and it was difficult to re-combine the separated groups into one. The riders and coaches need to be aware of the stretching and separation of the group, even if it does not occur immediately before the sprint as the positioning of a cyclist in the group would be important at that time.

Categorizing Bicycling Environment Quality Based on Mobile Sensor Data and Bicycle Flow Data

The bicycle is a healthy and sustainable transport mode due to its emission-free characteristics. To increase bicycle use, it is fundamental to provide bicycle-friendly environments. To better monitor bicycle environments, this study proposed the concept of bicycling environment quality (BEQ), which was defined by perceived satisfaction and conflict level. Data collection was conducted at 19 road segments in five sites located in Beijing, China. Then, speed-related and acceleration-related bicycling behavior indicators (BBIs) were extracted from data collected using sensors on mobile phones, while bicycling environment indicators (BEIs), such as bicycle flow, were extracted from recorded data. Taking the BBIs and BEIs as input attributes, a two-level BEQ classification assessment model based on a random forest (RF) algorithm was constructed. The proposed RF-based classification assessment model was able to produce approximately 77.35% overall correct classification. The results demonstrate the feasibility of using GPS data in evaluating BEQ. In addition, a novel dockless bicycle-sharing system (DBS)-based framework for bicycle traffic monitoring is discussed, which is of great significance in the sustainable development of bicycles. This study provides a theoretical method for objective BEQ assessment. It can further be used by planners and road administrators to monitor and improve BEQ and by individual cyclists for optimal route choice.

Application Two-Dimensional Pattern Development of Cycling Tights based on the Three-Dimensional Body Scan Data of High School Male Cyclist

This study develops an optimal two-dimensional (2D) pattern from three-dimensional human scan data by con sidering the cycling posture and dermatome of high school male cyclists. By analyzing the body surface change in the cycling posture and considering the dermatome of the lower limbs, the optimal cutting line setting and the development of cycling tights for individual cyclists were presented to provide data that could be used in the clothing industry. We designed three cycling tights to solve the size unsuitability. 3D design 1 is a non-extension design based on the analysis of the 3D human body scan data, in which parts were connected diagonally from the front of the knee to the back of the knee. 3D design 2 removed both the front and back to reduce air resistance during cycling. 3D design 3 did not have a cutting line on the front panel because of the air resistance during cycling in the front area. We analyzed the garment pres sure for 8 points of lower body and performed a subjective evaluation of the 3D designed tights and the current cycling tights. The 3D design 1 in this study was well received in the omphalion, thigh, and hip area, while 3D design 3 was well received in the omphalion, thigh, hip, and bottom bands. Therefore, the LoNE of 3D design 1 was applied to the front, and the hip cutting line of 3D design 3 was applied to the back.

Risk Factors for Illness-related Medical Encounters during Cycling: A Study in 102,251 Race Starters-SAFER XI.

There are limited data on risk factors associated with illness-related medical encounters (illME) in cycling events. The aim of this study was to determine risk factors associated with illME in mass community-based endurance cycling events. This is a retrospective cross-sectional study in the Cape Town Cycle Tour (109 km), South Africa, with 102,251 race starters. All medical encounters for 3 yr were recorded by race medical doctors and nurses. illME were grouped into common illnesses by final diagnosis. A Poisson regression model was used to determine whether specific risk factors (age, sex, cycling speed, and average individual cyclist wet-bulb globe temperature [aiWBGT]) are associated with illME, serious and life-threatening or death ME, and specific common illME. Independent risk factors associated with all illME during an endurance cycling event were slow cycling speed (P = 0.009) and higher aiWBGT (P < 0.001). Risk factors associated with serious and life-threatening or death ME were older age (P = 0.007) and slower cycling speed (P = 0.016). Risk factors associated with specific common illME were fluid and electrolyte disorders (females, older age, and higher aiWBGT) and cardiovascular illness (older age). Females, older age, slower cycling speed, and higher aiWBGT were associated with illME in endurance cycling. These data could be used to design and implement future prevention programs for illME in mass community-based endurance cycling events.

Cyclists' exposure to air pollution: in situ evaluation with a cargo bike platform.

Cyclists' exposure to air pollutants near roadways has been associated with numerous health effects. While the adverse health effects concerning aerosols have traditionally been assessed with data of particle mass concentrations, it appears that the number concentration is also another important indicator of toxicity. Thus, to holistically evaluate one's exposure to aerosol particles, assessments should be based on mass concentrations and number concentrations. In order to assess individual cyclists' exposure as they move through space and time, spatiotemporal high-resolution approaches are needed. Therefore, a mobile, fast-response monitoring platform was developed that uses a cargo bicycle as a base. Data of particle mass concentrations (PM1, PM2.5, PM10) and particle number concentrations (PN10) were collected along two different routes, one characterized by high-intensity vehicle traffic and one by low-intensity vehicle traffic. While high spatiotemporal heterogeneity was observed for all measured quantities, the PN10 concentrations fluctuated the most. High concentrations of PN10 could be clearly associated with vehicle traffic. For PM2.5, this relation was less pronounced. Mean particle concentrations of all measures were significantly higher along the high-traffic route. Comparing route exposures, the inhalation of PM2.5 was similar between both routes, whereas along the high-traffic route, cyclists were exposed to twice the particle number. We conclude that the cargo bike, featuring high-frequency mobile measurements, was useful to characterize the spatial distribution of mass concentrations and number concentrations across an urban environment. Overall, our results suggest that the choice of route is a key factor in reducing cyclists' exposure to air pollution.

Influence of peloton configuration on the interaction between sport cyclists and motor vehicles on two-lane rural roads

Cycling is a common activity on Spanish two-lane rural roads, mainly associated to sport and leisure, which resulted in 54 deaths in 2014. There is no scientific evidence about the risks associated to the interaction with motor vehicles of cyclists riding in a peloton. According to Spanish regulations, up to two cyclists can ride in parallel. This study compared different peloton configurations riding on a two-lane rural road segment. Three amateur cyclists rode along a road segment individually and grouped in pelotons with preset configurations: single bicycles, two bicycles in parallel, two in line, and different groups of three cyclists. Motor vehicle overtaking was observed and characterised from video cameras installed in the bicycles; speed and clearance were measured thanks to laser rangefinders on board. Moreover, the subjective risk perception at every overtaking event was recorded. Objective and subjective measures identified risky overtaking manoeuvres (low lateral clearance, high speed of vehicles, or high-risk perception). When cyclists rode in parallel, lower lateral clearances were found. At the same time, the overtaking vehicle speed was higher when individual cyclists were passed. These provided scientific support for criteria to ride in a peloton on two-lane rural roads.

Investigating cyclist interaction behavior through a controlled laboratory experiment

Nowadays, there is a need for tools to support city planners in assessing the performance of cycling infrastructure and managing bicycles and mixed flows. Microscopic and macroscopic bicycle traffic models can be used to fulfill this need. However, fundamental knowledge on individual cyclist interaction behavior (which should underpin these models) is hardly available in literature. Detailed bicycle traffic data are necessary if we want to gain insight into cyclist interaction behavior and develop sound behavioral theories and models. Laboratory experiments have been proven to be one of the most effective ways to collect detailed traffic data. For this reason, a controlled experiment aimed to investigate cyclist interaction behavior has been carried out at Delft University of Technology. This paper describes the experimental design, the resulting microscopic bicycle trajectories, and some preliminary results regarding one of the most common interaction situations: the bidirectional interaction. The preliminary results reveal how and to what extent cyclists interact in bidirectional cycling. It is found that cyclists perform a clearly-visible evading (collision avoidance) maneuver when they have face-to-face encounters. During these maneuvers, changes in speed and displacements in the lateral direction are observed. Cyclists start to deviate from their original path when they are around 30 m from each other, and they strongly prefer passing on the right-hand side. Moreover, the expectation of gender differences in cycling behavior reported in the literature is confirmed: our results show that women generally cycle more slowly than men and deviate more from their intended paths in face-to-face encounters. More observations will be available in the next stage of data analysis. These findings can be used to formulate improved microscopic bicycle traffic models for infrastructure design and policy development.

"Complete Streets" and Adult Bicyclist Fatalities: Applying G-Computation to Evaluate an Intervention That Affects the Size of a Population at Risk.

"Complete streets" policies require transportation engineers to make provisions for pedestrians, bicyclists, and mass transit users. These policies may make bicycling safer for individual cyclists while increasing the overall number of bicycle fatalities if more people cycle due to improved infrastructure. We merged county-level records of complete streets policies with Fatality Analysis Reporting System counts of cyclist fatalities occurring between January 2000 and December 2015. Because comprehensive county-level estimates of numbers of cyclists were not available, we used bicycle commuter estimates from the American Community Survey and the US Census as a proxy for the cycling population and limited analysis to 183 counties (accounting for over half of the US population) for which cycle commuting estimates were consistently nonzero. We used G-computation to estimate the effect of complete streets policies on overall numbers of cyclist fatalities while also accounting for potential policy effects on the size of the cycling population. Over a period of 16 years, 5,254 cyclists died in these counties, representing 34 fatalities per 100,000 cyclist-years. We estimated that complete streets policies made cycling safer, averting 0.6 fatalities per 100,000 cyclist-years (95% confidence interval: -1.0, -0.3) by encouraging a 2.4% increase in cycling but producing only a 0.7% increase in cyclist fatalities. G-computation is a useful tool for understanding the impact of policy on risk and exposure.

Investigating cycling kinematics and braking maneuvers in the real world: e-bikes make cyclists move faster, brake harder, and experience new conflicts

Pedelecs (e-bikes), which facilitate higher speeds with less effort in comparison to traditional bicycles (t-bikes), have grown considerably in popularity in recent years. Despite the large expansion of this new transportation mode, little is known about the behavior of e-cyclists, or whether cycling an e-bike increases crash risk and the likelihood of conflicts with other road users, compared to cycling on t-bikes. In order to support the design of safety measures and to maximize the benefits of e-bike use, it is critical to investigate the real-world behavior of riders as a result of switching from t-bikes to e-bikes.Naturalistic studies provide an unequaled method for investigating rider cycling behavior and bicycle kinematics in the real world in which the cyclist regularly experiences traffic conflicts and may need to perform avoidance maneuvers, such as hard braking, to avoid crashing. In this paper we investigate cycling kinematics and braking events from naturalistic data to determine the extent to which cyclist behavior changes as a result of transferring from t-bikes to e-bikes, and whether such change influences cycling safety.Data from the BikeSAFE and E-bikeSAFE naturalistic studies were used in this investigation to evaluate possible changes in the behavior of six cyclists riding t-bikes in the first study and e-bikes in the second one. Individual cyclists’ kinematics were compared between bicycle types. In addition, a total of 5092 braking events were automatically extracted after identification of dynamic triggers. The 286 harshest braking events (136 cases for t-bike and 150 for e-bike) were then validated and coded via video inspection.Results revealed that each of the cyclists rode faster on the e-bike than on the t-bike, increasing his/her average speed by 2.9–5.0 km/h. Riding an e-bike also increased the probability to unexpectedly have to brake hard (odds ratio = 1.72). In addition, the risk of confronting abrupt braking and sharp deceleration were higher when riding an e-bike than when riding a t-bike.Our findings provide evidence that cyclists’ behavior and the way cyclists interact with other road users change when cyclists switch from t-bikes to e-bikes. Because of the higher velocity, when on e-bikes, cyclists appear to have harder time predicting movements within the traffic environment and, as a result, they need to brake abruptly more often to avoid collisions, compared with cycling on t-bikes. This study provides new insights into the potential impact on safety that a cycling society moving to e-bikes may have, indicating that e-cycling requires more reactive maneuvers than does cycling traditional bicycles and suggesting that any distractive activity may be more critical when riding e-bikes compared to traditional bikes.

Novel Air Pollution Study Gauges Individual Cyclists’ Risks

By attaching an array of instruments to bike commuters in New York City, researchers aim to evaluate ambient pollution amounts and doses at the level of an individual cyclist.

A New Zealand Quasi-Experimental Study of Investment in Walking and Cycling Infrastructure and Encouragement Programmes

Background In 2010, two small cities in New Zealand, New Plymouth and Hastings, were selected as New Zealand’s two walking and cycling Model Communities. Over the 2010/11 and 2011/12 financial years, the programme consisted of $(NZ) 3.71 and $(NZ) 3.57 million respectively to New Plymouth and Hastings District Councils from central government for infrastructural changes (e.g. improved walkways and cycle lanes) along with information and education (e.g. campaigns to increase uptake and the confidence of individual cyclists). This was important to help address a national decline in active travel (walking and cycling for transport) observed over past decades, associated with increasing rates of obesity-related health conditions. Methods For our quasi-experimental study, Masterton and Whanganui were identified as suitable matched communities. They share some of the characteristics of the intervention cities, are similar in size and climate, and are interested in increasing active travel, but they did not have the additional central government funding. By comparing the intervention cities with the control cities, we could infer whether changes seen in Hastings and New Plymouth were due to the intervention or were part of a wider trend. A face-to-face survey obtained information on walking and cycling. We drew also on the New Zealand Travel Survey, a national ongoing survey of travel behaviour, which was conducted in the study areas. Lastly, we analysed distance travelled by cars in the study areas derived from licensing data. Results Relative to the control cities, the odds of trips being by active modes (walking or cycling) increased by 37% (95% confidence interval 8% - 73%) in the intervention cities between baseline and post-intervention. The net proportion of trips made by active modes increased by about 30%. Based on licensing data for all cars in the study areas, there was a 1.6% reduction in average annual vehicle kilometres travelled per passenger vehicle by the third year of the intervention. Conclusions The reduction in passenger vehicle travel was generally consistent with observed increases in the rate of active transport trips, assuming that active trips mainly replaced shorter car trips. For the small cities studied, improvements in infrastructure and associated programmes appear to have successfully arrested the general decline in active mode use evident in recent years.

Health impacts of cycling in Dublin on individual cyclists and on the local population

Abstract There is an emerging consensus that personal and societal health benefits in cycling largely outweigh the risks. However, there exists limited research into the health impacts experienced by individuals who take up cycling or the marginal societal benefits resulting from incremental uptake of cycling. This paper models and estimates the health impacts of individuals in Dublin taking up cycling. The paper utilizes the 2011 census data of Ireland and a Burden of Disease (BOD) approach is used to estimate health impacts on the individuals taking up cycling for their regular commute and on the rest of the local population separately. The health impact to an individual changing from private car to cycling ranged from a benefit of 0.033 Disability Adjusted Life Years (DALYs)/year to a loss of 0.003 DALYs/year. The marginal health impact to the local population ranged from no change to a benefit of 0.006 DALYs/year. Increases in cycling have a consistently positive impact on the health of the local population, regardless of the current modal split. The net expected health impacts to the individual cyclists are also positive in most cases. However, for some individuals in the 20–29 age group, the expected health impact may be small to negative, mainly due to a higher traffic collision risk. Where total impacts of scenarios are modelled the potential negative health impacts to some individuals may be masked by the overall positive health benefits of cycling to the local population. When promoting cycling as an alternative to driving to improve population health impacts, the risks to some cyclists should be managed and mitigated through safe road systems approaches.

Exploring the Influence of Simulated Road Environments on Cyclist Behavior

An increasing number of people are realiz- ing the advantages of bicycling, which has caused bicy- clist safety concerns and awareness to rise accordingly. This study aims to investigate the capability of combin- ing Virtual Reality technology and bicycle simulation for bicyclist behavior studies. An immersive interactive bi- cycle simulation was developed to explore how subject performance is influenced by virtual road environments through a well-controlled experiment with Oculus Rift headset. 30 people from 18-25 years old were chosen to be subjects, as they are in the highest injury rate per- centile. Results showed that the existence of bike lanes influences cyclist reactions, causing earlier and more braking to occur. Road hazard simulation and "Distance to Brake to Stop" measurement can provide useful in- sight into individual cyclist reactions to different types of road hazards. This study has provided evidence that given the nature of cycling on roads, virtual reality tech- nology can serve as both a safe and effective method to conduct more in-depth behavior studies.