Identification of safety effects of infrastructure related measures, Deliverable 5.2 of the H2020 project SafetyCube

Identification of safety effects of infrastructure related measures, Deliverable 5.2 of the H2020 project SafetyCub

Urban Street Networks and Sustainable Transportation

Urban street space is challenged with a variety of emerging usages and users, such as various vehicles with different speeds, passenger pick-up and drop-off by mobility services, increasing parking demand for a variety of private and shared vehicles, new powertrains (e.g., charging units), and new vehicles and services fueled by digitalization and vehicle automation. These new usages compete with established functions of streets such as providing space for mobility, social interactions, and cultural and recreational activities. The combination of these functions makes streets focal points of communities that do not only fulfill a functional role but also provide identity to cities. Streets are prominent parts of cities and are essential to sustainable transport plans. The main aim of the Street Networks and Sustainable Transportation collection is to focus on urban street networks and their effects on sustainable transportation. Accordingly, various street elements related to mobility, public transport, parking, design, and movement of people and goods at the street level can be included

Spatial analysis of bicycle use and accident risks for cyclists.

Most developed countries nowadays face environmental, health and mobility problems as a consequence of widespread car use. Policies are now being reappraised in favour of more sustainable modes of transport. In particular, bicycle use holds the potential to provide a ‘green’ and healthy alternative to car commuting. There are however still important barriers that discourage people cycling… This thesis aims at identifying some of the main factors that influence cycle commuting and cycling accidents. Identifying such factors would in turn provide greater support to enable policy makers developing supportive environmental conditions for cycling. In the first part of this thesis, we examine which factors influence the spatial variation of bicycle use for commuting to work at the level of the municipalities in Belgium. Special attention is paid to bicycle-specific factors and spatial econometric methods are used to account for the presence of spatial effects in the data. The second part of this thesis examines which factors are associated with cycling accidents in Brussels. Spatial point pattern methods extended to networks are used to compare the ‘locational tendencies’ of cycling accidents officially registered by the police with those that are unregistered. An innovative case-control approach, based on a rigorous sampling design of controls and an exhaustive data collection of spatial factors, is also proposed to allow modelling the risk of cycling accident along the Brussels’ road network. This thesis not only provides sound recommendations helping planners and policy makers to encourage bicycle use, but it also offers new research directions for pinpointing locations where accidents are more likely to occur.

Context sensitive road planning for developing countries

Includes bibliographical references (p. 207-228).The majority of South African urban poor live on the periphery of cities, travel long distances to work and school, and are dependent on public transport and walking or cycling (Non-Motorised Transport or NMT) for their travel needs. Road planning practice in South Africa continues to be largely automobile-centric. A need was identified to incorporate more contextual information into the transport planning process, to produce a more comprehensive, holistic and multimodal approach to practice. A description of the context, defined in terms of land use, socioeconomic, environmental and transport information, was developed and forms the basis of a method for making recommendations for road infrastructure provision. Data was incorporated using Spatial Multiple Criteria Assessment (SMCA), a Decision Support System and analysed in a GIS

Evaluating traffic safety network screening: an initial framework utilizing the hierarchical Bayesian philosophy

Highway crashes result in over 40,000 deaths per year (500,000 worldwide). Their impact on the national economy is estimated at more than 230 billion dollars. Highway safety is the top priority of the United States Department of Transportation (US DOT). Funds dedicated to the problem are expected to increase substantially.;Highway safety is a multidisciplinary issue. An important tool is the safety improvement candidate location (SICL) list. SICL lists list high crash locations for potential mitigation. SICL lists are developed using crash data. Crash frequency, rate, or loss is used to rank the worst locations. Classical statistical techniques are applied. In some cases, simple frequency analyses are used to draw attention to problem locations.;Simple ranked lists suffer from methodological and practical limitations. Chief among these is the inability to identify sites with promise , sites where mitigation has the best chance of success. Agencies representing engineering and enforcement generally examine top sites prior to resource dedication. This is resource intensive and efforts of different safety interests are often not well coordinated.;For over 20 years, empirical Bayesian (EB) has been proposed to address these limitations. EB identifies sites where mitigation might be most effective, increases estimate confidence, and provides information on relative site safety. EB is being widely implemented at the national level. State and local agencies continue SILL development based on long-standing procedures.;EB allows decision makers to more reliably estimate the crash reduction potential at specific sites. However, EB requires development of safety performance functions for road type classes. The technique also requires a priori development of accident modification factors. These requirements add significant expense.;Powerful computers and advanced statistical sampling techniques allow hierarchical Bayesian statistics to be applied to highway safety. Hierarchical Bayesian eliminates the need for a priori functions and factors. This approach can readily incorporate additional information. It can also explicitly identify important relationships between causal factors and safety performance. The approach uses data to define results, based on an analyst-specified level of uncertainty. This dissertation discusses SICL list development and evaluates the potential of Bayesian statistics to improve their utility

Identifikation und Untersuchung von Maßnahmen zur Verbesserung der Verkehrssicherheit an Arbeitsstellen an Autobahnen

Roadway work zones are hazardous, for both workers and motorists who drive through the complex array of signs, delineators and lane changes. Improper lane changing manoeuvres and possible vehicle encroachments in the activity areas may cause injuries to both the car occupants and road workers. Several studies agree that the presence of work zones significantly increases the risk of road crashes. Excessive speeding and high speed variances have also been identified as major causes of a large percentage of work zones crashes, injuries or fatalities. The main objective of this research was to determine safe and effective countermeasures for the reduction of speeds and speed variances within work zones. Furthermore, the influence of work zone layout features on crash occurrences was another important issue addressed with this study. An extensive accident analysis was therefore conducted on the stationary work zones of the Italian motorway network in order to identify the most critical layouts in terms of safety. The Empirical Bayes (EB) before-and-after method was performed in order to estimate crash modification factors (CMFs) associated with the installation of work zones on motorways. The findings of this part of the research have shown that all layout configurations that involve a crossover were associated with the highest values of CMFs. A number of countermeasures have been tested then in virtual reality through nine different configurations of the work zone crossover, in order to evaluate their effectiveness in reducing speeds and speed variances. The experiments investigated the effects of different speed limit sequences and alternative design features, such as wider lanes and median openings. Furthermore, the effects of different channelizing devices and perceptual treatments based on the Human Factor (HF) principles have also been investigated. The results of the experiments, performed on a total sample of 42 subjects, showed that, for all configurations, the drivers’ speeds are always higher than the posted speed limits and decrease significantly only in approaching the crossover by-passes. The implementation of higher speed limits, together with a wider median opening, led to a greater homogeneity of the driving speed. Perceptual countermeasures generally induced both the greatest homogenization of speeds and the largest reductions in mean speed values.Arbeitsstellen an Straßen sind gefährlich, sowohl für die Arbeiter als auch für die Verkehrsteilnehmer, die durch einen komplexen, von Verkehrszeichen, Straßenmarkierungen und Fahrstreifenwechsel geprägten Abschnitt fahren. Ungeeignete Fahrstreifenwechsel und dadurch verursachte Kollisionen innerhalb der Arbeitsstelle können zu Verletzten und Todesfolgen sowohl bei den Fahrzeuginsassen als auch bei den Straßenarbeitern führen. Verschiedene Untersuchungen stimmen darin überein, dass im Einflussbereich von Arbeitsstellen das Risiko für Verkehrsunfälle signifikant ansteigt. Unangepasste, zu hohe Geschwindigkeiten und große Geschwindigkeitsvarianzen wurden ebenfalls als wesentliche Ursachen für einen hohen Prozentsatz an Unfällen mit Personenschäden und Todesfolgen festgestellt. Das Hauptziel der vorliegenden Forschungsarbeit war es, sichere und wirkungsvolle Maßnahmen für die Reduzierung der Geschwindigkeiten und der Geschwindigkeitsvarianzen in Arbeitsstellen zu entwickeln. Weiterhin war der Einfluss der einzelnen Gestaltungsmerkmale der Arbeitsstelleneinrichtung auf das Unfallaufkommen ein anderer wichtiger Aspekt, der in dieser Studie adressiert wurde. Mit dieser Zielsetzung wurde eine umfangreiche Unfallanalyse für Arbeitsstellen längerer Dauer im italienischen Autobahnnetz durchgeführt, um die für die Verkehrssicherheit kritischsten Regelpläne zu identifizieren. Eine Vorher-Nachher-Untersuchung mit der empirischen Bayes-Methode (EB) wurde verwendet, um Änderungsfaktoren für das mit Arbeitsstellen verbundene Unfallaufkommen (Crash Modification Factor – CMF) zu schätzen. Die Ergebnisse dieses Teils der Forschung haben gezeigt, dass alle Regelpläne, die eine Überleitung auf die Fahrbahn der Gegenrichtung vorsehen, mit den höchsten Änderungsfaktoren (CMF) verbunden sind. Eine Reihe von Gegenmaßnahmen wurde daraufhin im Rahmen von neun unterschiedlichen Gestaltungsvarianten der Überleitung in der virtuellen Realität eines Fahrsimulators getestet, um deren Wirksamkeit auf die Verringerung der Geschwindigkeit und der Geschwindigkeitsvarianz zu bewerten. Die Experimente untersuchten die Auswirkungen von unterschiedlichen Folgen der Geschwindigkeitsbegrenzung und alternative Gestaltungsmerkmale wie z.B. breitere Fahrstreifen und Aufweitungen im Überleitungsbereich. Darüber hinaus wurden die Wirkungen von verschiedenen Einrichtungen für die Längsführung und die Aufmerksamkeitssteigerung untersucht. Die Ergebnisse der Fahrsimulator-Studie mit insgesamt 42 Testpersonen zeigten, dass die gefahrenen Geschwindigkeiten für alle Gestaltungsvarianten höher lagen als die jeweils vorgegebene Geschwindigkeitsbegrenzung und nur im nahen Zulauf zur Überleitung signifikant zurückgingen. Die Einrichtung höherer Geschwindigkeitsbegrenzungen in Verbindung mit einer größeren Aufweitung im Überleitungsbereich führte zu einer größeren Homogenität der gefahrenen Geschwindigkeiten. Maßnahmen, die der Aufmerksamkeitssteigerung dienen, führten sowohl zur größten Homogenität der Geschwindigkeiten als auch zur höchsten Verringerung der mittleren Geschwindigkeitswerte

Analysis of good practices in Europe and Africa

According to the Global Status Report on Road Safety 2015 of WHO (WHO, 2015), “road traffic injuries claim more than 1.2 million lives each year and have a huge impact on health and development”. Based on the WHO regions, there has been a deterioration in road fatality rates in the WHO Africa region from 24.1 fatalities per 100,000 inhabitants in 2010 to 26.6 fatalities per 100,000 inhabitants in 2013. Over the same period, there was an improvement in road fatality rates in the WHO Europe region. Road trauma in Africa is expected to worsen further, with fatalities per capita projected to double over the period 2015-2030 (Small and Runji, 2014). The SaferAfrica project aims at establishing a Dialogue Platform between Africa and Europe focused on road safety and traffic management issues. It will represent a high-level body with the main objective of providing recommendations to update the African Road Safety Action Plan and the African Road Safety Charter, as well as fostering the adoption of specific initiatives, properly funded. The main objective of work package 7 (WP7) is to analyse good road safety practices realised at country, corridor and regional levels in Africa and to compare these practices with those of other countries and with international experiences. Also included in this WP7, are good practices in road safety management and in the policy-making and integration of road safety with other policy areas. WP7 includes the definition of a transferability audit, tailored to Africa conditions that can be used to assess the suitability of road safety interventions in the context of African countries. Finally, promising local projects were identified, that may be implemented in selected African countries (Tunisia, Kenya, Cameroon, Burkina Faso and South Africa); to this end, a procedure for assessing the potential adaptability to the local contexts (transferability audit) will be developed in WP7 and applied to promising interventions. Following a successful transferability audit, a detailed concept definition of the retained interventions will be made by SaferAfrica participants and local road safety experts. Furthermore, factsheets on five key challenging African safety issues will be developed as synthesised working documents, containing all technical and financial information necessary for understanding the corresponding set of proposed interventions...

ASSESSING THE IMPACT OF BICYCLE TREATMENTS ON BICYCLE SAFETY: A MULTI-METHODS APPROACH

Compared to other modes, bicyclists are disproportionally affected by crashes considering their low mode share. There is evidence that crashes between bicyclists and motorized vehicle take place at road segments and signalized intersections where bicycle treatments (e.g., bike lanes) are present, urging for in-dept analysis of the safety impact of the various bicycle treatment types. Additionally, it is important to identify sensor types that have the potential to advance field data collection and traffic monitoring in multi-modal road environments. In this dissertation, three approaches, namely crash analysis, traffic conflict analysis, and analysis of driver speeding and glancing behavior, were implemented to investigate the safety impact of bicycle treatments at the segment- and the intersection-levels on bicycle safety. Prediction models were developed to predict bicycle-motorized vehicle crashes at road segments and signalized intersections, and traffic conflicts between straight-going bicyclists and right-turning vehicles at signalized intersections. Driver speeding and glancing behavior was analysed for the segment and the intersection levels. A mode classification framework to classify trajectories recorded using a radar-based sensor was developed to test the feasibility of using radar-based sensors in field studies. The findings of this dissertation contribute to bicycle safety research in terms of quantifying the safety impact of various bicycle treatment types and how to assess and also, by showing how to assess bicycle safety. The findings of this research have the potential to stand as a valuable tool for transportation policymakers and officials in charge of establishing safe bicycle networks