Effects Of Highway Geometric Elements On Accident Modelling

Abstract

Road accident fatalities have been on an increasing trend for the last decade or so in India. Hence traffic safety management has emerged as a topic of discussion for researchers all over the world. Hence accident modeling on different factors causing them has to be conducted. Accident modeling helps us to know the real causative agents behind an accident to occur. The effect of one cause can be greater than the other. And those causes can only be known from accident modeling. In this paper we have tried to divide this accident modeling techniques into two different categories based on the location of road i.e. accidents on urban roads and on rural roads. In both urban and rural road accident studies it was seen that mainly regression techniques like linear, multi-linear, logit and poisons regression have been used for modeling the road crashes. It was also marked that mostly authors have tried to research on one cause and go deep into it rather considering all factors at a time. From the studies it was found that speed and age along with gender has been the area of study for accident causes in urban areas whereas in rural

roads mostly all authors have limited their studies to speed on roads and has been noted as the major cause of accidents in rural areas. This paper has tried to review as much papers as possible and various gaps in research along with future scope of study in this area has been indicated. Starting from the basic models like negative binomial/Poisson’s model to the logistic and linear regressions to the new modeling techniques involving genetic mining and fuzzy logics have been discussed explicitly in the paper. A series of surveys on accident investigation models show a wide variety of models, dedicated to specific

industrial applications, domains and investigation aspects. In particular the investigation of human factors is exposed to a wide diversity of models. In reviewing such models, the majority proves to be a derivate from the Reason’s Swiss Cheese causation model or the Rasmussen model on system hierarchy. Most of the models origin from the process industry and the energy sector. Application in the aviation industry has revealed their conceptual limitations. Due to their simplifications and lay interpretations, their intervention potential in practice is limited to linear solutions. In order to cope with socio-technological interactions in a multi-actor perspective, a full systems engineering design approach should be applied in a mission specific operating envelope. Such an approach is submitted to three paradigmatic shifts in investigation methodology. First; disengagement is required between event modeling and systems modeling. Second; a distinction in two design classes is required. A distinction is made between linear interventions within the existing design envelope and second order interventions focusing on expansion of the design solution space. Third; designing safer solutions in a multifactor systems environment requires prototyping, virtual system model simulation and testing of limit state scenarios. Based on these constraints, a framework for safety enhancement is described, derived from experiences in the aviation industry itself.This paper outlines how geometric design standards for undivided interurban roads have changed over time in response to financial, safety and environmental constraints. Initially, the dimensions of each road element were selected to provide a safe road layout and a desirable level of service.