Modelling of road safety attributes in the case of road network development on regional level in Poland

The paper presents the Polish evaluation procedure of the influence of new road infrastructure on traffic safety. The presented methodology has been widely used on national roads in Poland since 2009. According to the Polish requirements, the evaluation should be conducted on an early stage of the designing process and together with the Cost Benefit Analysis (CBA) and environmental analysis, as it plays an important role in the final assessment of alternative solutions. The main goal of the procedure is to create the rank of planned investments (alternatives) and their evaluation of the traffic safety level (indirectly, gives also the input data for CBA). The analysis is based mostly on traffic volume and traffic forecasts. Due to the necessity of analysisng the whole area of influence (road network) in traffic safety features on designed road, it is important to take into consideration reliable traffic forecasts developed with modelling tools. For the chosen areas, it is necessary to identify road sections with high accident concentration (number of fatal accidents that have occurred in the previous years) and estimate impact of developed road system on traffic safety. The example of implementation of the presented procedure in the case of planned express road S1 (southern Poland) constitutes an important part of this paper. The paper consists of sensitivity analysis of the presented procedure and presents final ranking of tested variants.