A Geo-Statistical Analysis of Road Mortality in the Enlarged EU

This paper aims at showing and understanding the spatial regional disparities hidden behind average national statistics on road fatalities in Europe; special attention is given on the EU last enlargement. The work is not limited on differences descriptions, but unveils what is hidden behind the observed infra-national heterogeneity in terms of road risk. It is indeed common practice to compare countries in terms of road safety performance and to rank them in terms of a risk indicator such as the mortality rate, which is often expressed by the number of fatalities due to road accidents per 100,000 inhabitants. Some countries are known for their very bad risk records and are often pointed out by national or international authorities, without any understanding of the regional differences hidden behind a national mean value. The data analysis shows that changes in the level of spatial aggregation of the data produce significant differences in the variables describing the level of road safety, and hence in operational recommendation and conclusions. Beside the differences in national conditions and polices, the regional differences in road environment characteristics, traffic performance, road user mix, travel speeds, seat-belt use, and availability of emergency care have been major contributors to these variations. Road safety professionals and decision makers should be aware of the differences existing when trying to reduce road toll of the country in sustainable and cost-effective way.

Pedestrian Risk Taking While Road Crossing: A Comparison of Observed and Declared Behaviour

AbstractThe objective of this research is the comparative analysis of observed and declared behaviour of pedestrians as regards road crossing in urban areas. A field survey was carried out, in which a panel of 75 young and middle-aged pedestrians (out of which 40 males) were asked to take 8 short walking trips (each one corresponding to a different walking and crossing scenario and involving one road crossing) in the Athens city centre in Greece. This allowed to record their crossing behaviour in different road and traffic conditions, including residential roads, main urban roads and major urban arterials. The same individuals were asked to fill in a questionnaire on their crossing behaviour and preferences at different road and traffic environments, as well as other related questions concerning their travel motivations, their mobility characteristics, their risk perceptions and preferences etc. A comparative analysis of their declared and observed crossing behaviour was carried out. More specifically, for each pedestrian, the rate of mid-block crossing and diagonal crossing during the walking tasks was calculated for the different road and traffic conditions. These were compared to their questionnaire responses on their crossing behaviour in different road and traffic conditions. The results suggest that, overall, pedestrians observed behaviour is in accordance with their declared behaviour. However, there is a non-negligible share of pedestrians, whose observed and declared behaviour were discordant, either at specific road and traffic conditions or overall. For instance, there were pedestrians who declared that they never cross at mid-block on major urban road but did so during the survey. Moreover, there were pedestrians who declared high frequency of mid-block crossing, but did not implement these crossing practices during the survey. The degree of discordance between pedestrian observed and declared behaviour was further analysed in relation to pedestrian demographics. A weak tendency was identified for female pedestrians to have more discordance between observed and declared crossing behaviour on residential roads, and the same was the case for young pedestrians in all road and traffic conditions. Overall, the results suggest that, while most pedestrians appear to have consistent declared and observed behaviour, there may all deviate from their general “profile” under specific conditions

Simuler les interactions piétons-automobilistes dans un environnement urbain

An agent-based model - SAMU - has been designed, which allows exploring pedestrians-drivers interaction in a virtual urban environment. Complex dynamics are obtained from simple behaviours. The key elements of SAMU are presented and discussed

Exploring road mortality ratios in Europe: national versus regional realities

The paper analyses the geographical pattern(s) of road mortality in western Europe for three standard levels of data aggregation. A new adjusted road mortality ratio is proposed. Unlike most mortality ratios, the standardization uses population density rather than age and sex. The hypothesis to be tested is that changes in the level of spatial aggregation of the data produce significant differences in the values of some basic descriptive statistics, and hence in operational conclusions. The paper shows that population density works as a proxy for structural factors that may be difficult to change by policies and that working with 264 regions confirms the north-south divergences in terms of road safety in Europe but also stresses the local or regional differences due to political, geographical, economic, environmental and statistical disparities. Safe countries include unsafe regions, and there are safe regions in unsafe countries. Decision makers should be aware of this when comparing countries

Analyse spatiale des déplacements des piétons en milieu urbain du point de vue des traversées afin d’évaluer l’exposition au risque d’accident

A pedestrian is mainly exposed in urban area to traffic accident when crossing the street. A pedestrian in a trip spent time during a crossing in a micro-environment characterized by the volume and the speed of the flows of vehicles. The objectives of the research are: 1. to define the methodology to collect by survey and to code in a GIS, information about the trip and the crossings made on the urban network by a pedestrian and to match it with information on traffic flows on the street network,2. to test this methodology on a sample of trips made by adult pedestrians in order to quantify the length of the trip, the number of crossings, the part of crossings made at mid-block or junctions on a specific urban setting, la ville nouvelle de Villeneuve d'Ascq

Regional analysis of road mortality in Europe

Background: Road accidents are the tenth leading cause of premature death worldwide and, based on current trends, are likely to become the third leading cause of disability-adjusted life years lost by 2020. Road mortality varies in time and space both between countries and also between regions within the same country. Identifying and understanding the background of regional differences may lead to better understanding of the sources of road accidents, and enable the application of more effective road safety policies. Methods: A Bayesian ecological regression model based on a unified generalized linear mixed model framework is introduced. Population density and country (affiliation) were used as covariates and were fitted into the model at the four levels of spatial aggregation known as ‘nomenclature of statistical territorial units (NUTS) regional classification’. Results: Population density has a significant influence on road mortality. For all countries together, the elasticity estimate is -0.32, meaning that a 10% increase in population density is linked to a 3.2% decrease in road fatalities. A multi-level model defined at the NUTS-3 level, taking into account the NUTS-2 aggregation, enables infraregional variances in road mortality to be taken into account and produces the most reliable estimates of the model parameters. Variation in the Bayes relative risk (the mortality ratio ‘standardized’ by population density and country effect) is highest at the NUTS-3 level, but is lower at country level and NUTS-2 level, which suggests that other important underlying factors are responsible for the variations in road mortality between regions. Mapping the Bayes relative risk enables the identification of regions that should be targeted by national and regional policies. Last but not least, a new ranking of European countries according to their road mortality risk, adjusted for population density, is presented

Utilisation des systèmes d'information géographique (SIG) dans la gestion des risques routiers en milieu urbain

L'intégration de la dimension spatiale dans l'analyse d'accidents routiers était moins bien traitée avant l'intégration des SIG (Systèmes d'Information Géographique) et leurs outils d'analyse spatiale qui nous ouvrent de nouvelles perspectives. La thèse vise à adapter ou autrement dit "customiser" certains modèles de risque d'accident en milieu urbain développés par le TRL en Grande-Bretagne aux contextes français et d'un pays arabe du Moyen-Orient. De plus une simplification du recueil et du codage des données nécessaires à ces modèles est proposée afin d'implémenter ces modèles plus facilement pour la gestion des risques routiers ; bien identifier et localiser les enjeux des risques sur le réseau en milieu urbain est possible grâce à l'utilisation de la technologie des SIG comme outil d'aide à la décisionThe integration of spatial dimension in the analysis of road accidents was less well treated before the integration of GIS (Geographical Information Systems) and their tools for spatial analysis which open a new perspective to us. The thesis aims to customize some urban accident risk models developed at the Transport Research Laboratory in England to the context of French and Arabic countries in the Middle East. Some simplification of the data collection and coding necessary for these models, is proposed in order to implement these models in an easier way for road risk management ; A fair identification and localization of the major problems of road risk in urban area is now possible through the use of GIS technology as a tool for decision-making.ST ETIENNE-BU Droit-Let-Eco-Huma (422182101) / SudocSudocFranceF

Stop-and-go waves induced by correlated noise in pedestrian models without inertia

Stop-and-go waves are commonly observed in traffic and pedestrian flows. In most microscopic traffic models, they occur through a phase transition and instability of the homogeneous solution after fine tuning of parameters. Inertia effects are believed to play an important role in this mechanism. In this article, we present a novel explanation for stop-and-go waves based on stochastic effects in the absence of inertia. The model used is a first order optimal velocity (OV) model including an additive stochastic noise. A power spectral analysis for single-file pedestrian trajectories highlights the existence of Brownian speed residuals. We use the Ornstein-Uhlenbeck process to describe such a correlated noise. The introduction of this specific colored noise in the first order OV model allows describing realistic stop-and-go behavior without requiring instabilities or phase transitions, the homogeneous configurations being systematically stochastically stable. We compare the stochastic model to deterministic unstable OV models and analyze individual speed autocorrelation to describe the nature of the waves in stationary states. We apply the approach to pedestrian single-file motion and compare simulation results to real pedestrian trajectories. The simulation results are quantitatively very similar to the real trajectories. We discuss plausible values for the model parameters and their meaning. (C) 2019 Periodical Offices of Chang'an University. Publishing services by Elsevier B.V. on behalf of Owner