Investigation of hit-and-run crash occurrence and severity using real-time loop detector data and hierarchical Bayesian binary logit model with random effects

Objective: Most of the extensive research dedicated to identifying the influential factors of hit-and-run (HR) crashes has utilized typical maximum likelihood estimation binary logit models, and none have employed real-time traffic data. To fill this gap, this study focused on investigating factors contributing to HR crashes, as well as the severity levels of HR.

Methods: This study analyzed 4-year crash and real-time loop detector data by employing hierarchical Bayesian models with random effects within a sequential logit structure. In addition to evaluation of the impact of random effects on model fitness and complexity, the prediction capability of the models was examined. Stepwise incremental sensitivity and specificity were calculated and receiver operating characteristic (ROC) curves were utilized to graphically illustrate the predictive performance of the model.

Results: Among the real-time flow variables, the average occupancy and speed from the upstream detector were observed to be positively correlated with HR crash possibility. The average upstream speed and speed difference between upstream and downstream speeds were correlated with the occurrence of severe HR crashes. In addition to real-time factors, other variables found influential for HR and severe HR crashes were length of segment, adverse weather conditions, dark lighting conditions with malfunctioning street lights, driving under the influence of alcohol, width of inner shoulder, and nighttime.

Conclusions: This study suggests the potential traffic conditions of HR and severe HR occurrence, which refer to relatively congested upstream traffic conditions with high upstream speed and significant speed deviations on long segments. The above findings suggest that traffic enforcement should be directed toward mitigating risky driving under the aforementioned traffic conditions. Moreover, enforcement agencies may employ alcohol checkpoints to counter driving under the influence (DUI) at night. With regard to engineering improvements, wider inner shoulders may be constructed to potentially reduce HR cases and street lights should be installed and maintained in working condition to make roads less prone to such crashes.     

Establishing A Earth Observation Product Service For The Terrestrial Carbon Community: The Globcarbon Initiative

'Greenhouse gases', especially carbon dioxide, are intimately connected to climate change. To understand the future evolution of the climate system and find ways to manage the concentration of atmospheric carbon dioxide, the processes and feedbacks that drive the carbon cycle must first be understood. However, our current knowledge of spatial and temporal patterns is uncertain, particularly over land and in regions of potentially high sensitivity to change like the boreal zone. The European Space Agency (ESA) GLOBCARBON project aims to generate fully calibrated estimates of at-land products quasi-independent of the original Earth Observation source for use primarily in Dynamic Global Vegetation Models, but also as a contribution to the Global Carbon Project, a cooperation between the International Geosphere Biosphere Programme, International Human Dimensions Programme and the World Climate Research Programme to aid understanding of global carbon cycling. The service will feature estimation of global burned area, the fraction of absorbed photosynthetically active radiation (f_APAR), leaf area index (LAI) and Vegetation Growth Cycle. The demonstrator will focus on ten complete years, from 1998 to 2007 when overlap exists between ESA Earth Observation sensors and others that are synergistic. However, the system will be flexible so that it is not dependent on any single satellite sensor and therefore can be retrospectively applied to existing archives and used with future satellite sensors.     

Integration of standardized environmental and quality management systems audits

In the last few years, many organizations have chosen to implement standardized Management Systems (MSs), such as the ones based on ISO 14001 and ISO 9001. However, few studies exist on how firms carry out the process of auditing these MSs.Our goal is to study how companies with more than one standardized MSs conduct the audits and to which extent they integrate the audit elements in order to benefit from the advantages of having a sole, integrated audit system.We provide four case studies and confirm the idea that firms with more than one MS integrate their audits. However, the degree and specific characteristics of this integration vary in the different companies analyzed.This paper contains one of the first qualitative empirical studies regarding the integration of MSs audits. The study provides an original contribution to the understanding of whether and how the four case study organizations have integrated certain aspects of the audit systems, for instance, the human resources, time, and audit inputs and outputs.     

Perspectives on social capacity building for natural hazards: outlining an emerging field of research and practice in Europe

Social capacity building for natural hazards is a topic increasingly gaining relevance not only for so-called developing countries but also for European welfare states which are continuously challenged by the social, economic and ecological impacts of natural hazards. Following an outline of recent governance changes with regard to natural hazards, we develop a heuristic model of social capacity building by taking into account a wide range of existing expertise from different fields of research. Particular attention is paid to social vulnerability and its assessment, as well as to risk communication and risk education as specific strategies of social capacity building. We propose to distinguish between interventionist and participatory approaches, thus enabling for a better understanding of existing practices of social capacity building as well as their particular strengths and weaknesses. By way of conclusion, we encourage more research on social capacity building for natural hazards in the European context which at present is highly diverse and, at least in parts, only poorly investigated.