The available knowledge of traffic safety at roundabouts is not a completereference for geometric design; where there are organizational schemes forjunctions characterized by a geometric design, quite different driving behavioursare required from those that are observable at roundabouts.This is very frequent in urban areas, where the existing constraints,particularly physical ones, often render it necessary to make “compromisechoices” relating to one or more geometric features of the roundabout (centralisland shape, circulatory roadway width, symmetry and number of the arms,entry width, etc). The objective of this study is to explain the accidentphenomenology of this kind of road scheme, with reference to the most frequentaccidents for the junctions examined in different traffic and risk exposureconditions. The study also intends to verify the effectiveness of risk analysis bymeans of an infrastructural scenarios method, devised in previous research by theauthor.In this paper, in order to deduce the contribution of the accident-causingfactors to each type of accident and to evaluate the relative contribution indetermining the level of risk for the different scenarios, the risk model has beenchecked considering specific accident classes. The results confirm theapplicability of the risk evaluation method to urban road schemes, characterizedby peculiar geometric features such as the impossibility of applying the safetymethods proposed in the literature regarding traditional roundabouts; moreover,in the terms of greatest interest to road designers, they provide useful elementsfor evaluating the effects of deviations from design rules on urban road safety.
|Numero di pagine||11|
|Stato di pubblicazione||Published - 2004|
All Science Journal Classification (ASJC) codes