In-built network-wide road safety assessment methodologies for rural roads.

OBJECTIVE: Road traffic crashes are mainly caused by three concurrent factors: infrastructure, vehicle, and human factors. Regarding infrastructure, in recent decades, a series of management tools and procedures called Road Infrastructure Safety Management (RISM) have been proposed. The aim of RISM procedures is to support road authorities in the prevention and mitigation of future road traffic crashes. One of these procedures is the In-built Road Safety Assessment (IRSA) methodology. The peculiarity of an IRSA methodology is the underpinning method used to assign a score to a road section with the aim of identifying those road sections in a network with safety-related infrastructure deficiencies. The objective of this paper is to provide an overall literature review of existing methodologies used worldwide for network-wide road safety assessment for rural road. METHODS: The review was conducted following the guidelines provided by Joanna Briggs Institute (JBI) and the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA-P) checklist 2020. The characteristics of these methodologies were compared with respect to the following research questions: What are the general characteristics of IRSA methodologies? What risk method/index is applied? Which data collection method/technique is used? What types of road parameters are considered for the assessment? What is the level of expertise needed to implement the methodology? Where and how are the results validated? RESULTS: As a result, 14 IRSA methodologies were identified. Also, the review showed that similar road parameters were used including: operating speed, road surface, low curve radius, poor sight distance (horizontal and vertical curves), lane width, undivided road (median type), shoulder width, sight obstructions (landscape, obstacles and vegetation), absence of traffic signs and road markings, traffic flow (AADT), intersection quality and density of intersections/lateral accesses. CONCLUSIONS: Despite these similarities, some differences were observed in risk formulation, safety quantities of parameters, level of expertise required, and validation of studies. Researchers may use these findings to develop future road safety assessment methodologies, while road practitioners can make use of this in identifying suitable network-wide assessment methods for safety assessments of road infrastructures. Finally, a series of recommendations for future research work on IRSA methodologies is suggested.

Developing improved crash prevention approaches through in-depth investigation of motorcycle crash causation patterns.

Despite advancements in road safety, Powered Two-Wheelers (PTWs) remain a vulnerable group with disproportionately high crash rates. This paper presents an in-depth analysis of PTW crashes in six European countries, with a case study of Loss of Control in Curves (LoCC), to address the gap between crash causation and prevention. By examining crash causation factors and their linkage to prevention strategies, the study illustrates various approaches for connecting causes and countermeasures. These approaches, which are applicable to different crash scenarios, include looking forward in the crash causation chains, looking backward, looking at only the last cause (critical events), or the first cause, or following a systemic approach. The research introduces a set of guidelines following the safe system approach, aiming to enhance the understanding of crash prevention among policymakers. The systemic approach to countermeasures, bridges the shortcomings of traditional crash causation studies that may exhibit bias or a narrow focus on "root causes". The proposed approach emphasizes the need for a comprehensive view of crash scenarios (i.e., considering the entire crash causation chain or multiple causation chains) and ensuring that preventive measures address the full spectrum of the system. It also takes in to account external factors such as cost, benefits, and politics, leading to improved road safety outcomes. The study findings are significant for researchers, since it is a step forward in in-depth crash causation studies, as well as road practitioners and policymakers, in providing a strategic framework for more effective and efficient road safety interventions.