Now showing 1 - 6 of 6
  • Publication
    Short-term forecasting of bicycle traffic using structural time series models
    Short term forecasting algorithms are widely used for prediction of vehicular traffic flows for adaptive traffic management. However, despite the increasing interest in the promotion of cycling in cities, little research has been carried out into the use of traffic forecasting algorithms for bicycle traffic. Structural time series models allow the various components of a time series such as level, seasonal and regression effects to be modelled separately to allow analysis of previous trends and forecasting. In this paper, a case study at a segregated bicycle lane in Dublin, Ireland was performed to test the forecasting accuracy of structural time series models applied to continuous observations of cyclist traffic volumes. It has been shown that the proposed models can produce accurate peak period forecasts of cyclist traffic volumes at both 1 hour and fifteen minute resolution and that the percentage errors are lower for hourly forecasts. The inclusion of weather metrics as explanatory variables had varying effects on the forecasting accuracies of the models. These results directly aid the design of traffic signal control systems accommodating cyclists.
    Scopus© Citations 8  330
  • Publication
    Dear Diary: Reports of Uncontrolled Experiments in Cork
    (Irish Transport Research Network, 2017-08-29) ; ; ; ;
    Perceived risks of cyclists is a deterrent for increasing cycling activity in a mixed mode network. This fact is particularly relevant for networks where cycling is becoming popular. This paper presents an uncontrolled study in Cork where a number of cyclists kept a diary log of incidents and perceptions of risk for a period of time while traveling. The risk ratings were carried out based on a 10 point scale and the results of this study avoid the Hawthrone Effect. The cyclists provided self-reported data on risk ratings related for a range of routes in Cork and this paper forms a first evidence base around the perception of safety of cyclists in Cork. Interactions with motorists, conflict points, condition of the infrastructure and other factors were investigated and the study attempts to provide a better insight to the perceived safety of cyclists in a city where interest and investment around cycling is on the rise. Several consistent themes emerged from the diary entries. These include, lack of awareness, lack of respect towards cyclists in a mixed mode network, lack of space and time given to the cyclists for manoeuvre, the state of cycling facilities, motor vehicles cutting across cyclists and late or no indication by motorists. The study provides insight to cyclist-vehicle interaction in an emerging cycling network and encourages further research in the area of culpability and risk ratings.
      168
  • Publication
    Quantifying the Health Impacts of Active Travel: Assessment of Methodologies
    (Taylor & Francis, 2015-05-12) ; ;
    In the past several years, active travel (walking and cycling) has increasingly been recognized as an effective means of improving public health by increasing physical activity and by avoiding the negative externalities of motorized transport. The impacts of increased active travel on mortality and morbidity rates have been quantified through a range of methodologies. In this study, the existing publications in this field of research have been reviewed to compare and contrast the methodologies adapted and to identify the key considerations and the best practices. The publications were classified in terms of the health summary outcomes and exposure variables considered, the model structures used in the studies and the impact of these choices on the results. Increased physical activity was identified as the most important determinant of the health impacts of active travel but different ways of quantifying these health impacts can lead to substantial differences in the scale of the impact. Further research is required into the relationship between increased physical activity and health effects in order to reach consensus on the most reliable modelling approach for this important determinant of benefits. Critical discussions on other exposure variables have also been provided to ascertain best practices. Additionally, a logical flow of the modelling processes (and their variations) has also been illustrated which can be followed for developing future studies into the health impacts of active travel.
    Scopus© Citations 48  639
  • Publication
    Health impacts of cycling in Dublin on individual cyclists and on the local population
    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.
    Scopus© Citations 14  364
  • Publication
    Analysis of heart rate variability amongst cyclists under perceived variations of risk exposure
    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.
      385Scopus© Citations 24
  • Publication
    Health, environmental and travel cost impacts of urban cycling in Dublin, Ireland
    (ICE Publishing, 2019-03-18) ; ;
    Cycling as a mode of transport avoids the negative external costs of driving such as air pollution, carbon dioxide emissions and noise and can also reduce the public health costs associated with physical inactivity. However, increased cycling may also have disadvantages such as increased exposure to air pollution and risk of traffic collisions. A number of studies have developed methods to quantify these health and environmental impacts and have shown that the overall impact of increased cycling is positive. However, while minimising travel costs is traditionally the main objective of transport planners, these studies have not included travel cost impacts in their analyses. In this study, the impacts of a modal shift towards cycling are quantified, taking into account health, environmental and travel cost impacts. It was found that the health and environmental impacts of increased cycling in Dublin, Ireland, would be strongly positive, mainly due to the health benefits of physical activity. When travel costs are also included in the analysis, the central estimate of net impact remains positive but the uncertainty increases considerably. This underscores the importance of the transport and health sectors working together to maximise the social welfare resulting from transport projects.
    Scopus© Citations 4  440