# A Unified Approach for Risk Assessment of Road Crash Barriers Using Bayesian Statistics
## 1 Introduction  
The issue of traffic accidents is a long-standing problem that requires constant attention. The Czech Republic, as well as other EU countries, is required to adopt a plan to reduce the consequences of traffic accidents, known as the White Paper [1]. This document serves as a foundation for several national strategic documents, including the National Road Safety Strategy in the Czech Republic [2; 3]. One of the main goals of current policy is to promote the \"Vision Zero\" idea [4], which represents a traffic system without deaths or serious injuries. While achieving this goal in the coming years may be merely utopian, it is still believed to be possible or that it will be possible to come close to doing so in the future [5].  
The implementation of this policy requires comprehensive developments in the field of road safety. In order to describe a road as safe, it is necessary that the road fulfills two basic conditions--that its safety features are self-explanatory and flexible [6; 7]. One of the tools to achieve this goal is Road Safety Inspections. This tool is integrated by legislation into practice in many countries around the world [8; 9; 10; 11; 12; 13]. It is essential to improving road safety.  
The principle of road safety is to identify the risk factors of the selected road section. Subsequently, measures are proposed to eliminate them. The inspection team can rate the identified risk factors with three levels of risk severity: low, medium, and high [8]. The rating helps the inspection client to prioritise when deciding whether to address risk factors, and if so, which ones to address and in what order of priority. The inspection team determines the severity of the risk based on their qualifications and experience. The circumstances involved in the occurrence of accidents are complex, and estimating the level of safety risks identified is a challenging task [14; 15].  
However, the description of this risk rating scale is exceptionally general. According to the experience of road safety auditors and road managers, the severity of the same types of defects differs. The rating is particularly problematic in the area of restraints, as that is perceived differently by individual auditors who assess them subjectively. Specifically, this pertains to road restraint systems, which include, for example, crash barriers, crash cushions, and other safety features, as well as safety equipment of the road. The primary function of these features is to absorb energy when cars crash. The precondition for fulfilling this function is their absolute functionality, which can only be achieved if the road restraint systems are properly designed and implemented [16; 17; 18; 19].  
The primary objective of the manuscript is to explicitly standardize and subsequently validate the riskiness of the identified traffic safety deficits in the area of interceptor systems. The benefit of implementing a clearly defined methodology will allow road safety auditors to accurately rate the riskiness of restraint systems. The topic of this article is focused on this category because assessment of the riskiness of these systems from the point of view of professional practice is often a subject of discussion and a matter of opinion. In addition, the article can provide road managers with a tool to help them focus on assessing the riskiest defects and prioritising the reconstruction of selected objects. Thus, they will be able to make more economical use of the financial and human resources at their disposal and avoid investing more time on less serious problems that do not significantly affect the health consequences of a traffic accident [6; 20]. The risks are referenced to the crew of an average passenger car.