# Comparison of Condition Rating Systems for Bridges in Three European Countries
## 1 Introduction  
Bridges are key parts of transportation systems worldwide [1, 2]. In most cases, inadequate control and preservation over time have led to the constant deterioration of their structural conditions, also compromising their safe usage, despite their importance for the social and economic well-being of the communities [3]. The collapses that have occurred over time around the world demonstrated how extremely vulnerable bridges are to both human and natural causes, including overloading, incorrect design, inadequate inspection, and lack of maintenance. In just the last decade, more than 60 bridge failures occurred worldwide, followed by an equally large number of fatalities [4]. In the recent past, the European public was shocked by the disastrous failure of Viadotto Polcevera also known as Ponte Morandi in Genoa, Italy (2018). This collapse resulted in 43 fatalities. However, this is not the only collapse of a bridge in the recent past in the European continent.  
The ageing infrastructure which was largely built in the post-war period is reaching its limit of service life and needs to be assessed. Therefore, European administrators and researchers have focused on the development of proper condition rating systems for bridges which should calm the public's concerns and ensure safe bridge infrastructure across the continent. Currently, European engineers use common standards for the design of structures which are called Eurocodes. Consequently, the approach in design procedure differs only in very specific situations which are listed and described in the national annexes of individual states. Current Eurocodes provide specific rules for newly designedbridges, while EC8-3 [5] is specifically devoted to the assessment and retrofitting of existing structures, even if it deals mainly with buildings, although the revision in progress in 2021 also includes bridge structures. Hence, the condition rating system varies from country to country and can lead to different conclusions in the decision-making process. Therefore, the need for a common condition rating system has arisen. A standard rating system may have many advantages, including providing an objective comparison of the health state of infrastructures on the European continent and thus supporting the process of allocating economic funds aimed at rehabilitation and modernization of the infrastructural assets.  
The presented paper aims to describe currently used bridge condition rating systems in Italy, Slovakia, and Portugal, with the aim of highlighting differences among these European countries and supporting the process of creating standardization within the European Union. This paper originates from an international collaboration between three European universities (Universita Politecnica delle Marche in Italy, University of Zilina in Slovakia, and University of Minho in Portugal) who share a common interest in the health assessment of bridges and who decided to provide this work as a starting point to propel the standardization process in Europe. For each of these countries, the current code prescriptions about existing bridges are introduced and described in depth, discussing the methodologies and parameters that lead to achieve the outcomes regarding the state of the existing bridges. Moreover, the bridge classification procedures currently adopted in each country are proposed to obtain a sort of attention or risk class about a bridge. In Italy, the new guidelines for existing bridge assessment and maintenance propose a class of attention differentiated into five levels of increasing risk. In Slovakia, the classification procedure is based on a load-carrying capacity coefficient and a bridge can fall into one of the seven possible classes. In Portugal, the assessment of bridges is made through an indicator, named condition state, with six possible classes, where, based on inspection, damages are evaluated by severity, extension, damage development and consequences.