Principal Component Analysis of Contributing Factors for Level of Safety Service

To overcome the shortcomings of safety evaluation methods based upon traffic crash and traffic conflict, the concept of level of safety service for intersections is proposed. Considering the ability of obtaining evaluation data for developed and developing countries, the models of level of safety service will be developed from the contributing factors. Based upon the qualitative analysis of factors, the Principal Component Analysis is applied to condense contributing sub-factors. The analyzed result is that several sub-factors of partial contributing factors are removed, but most valuable information is kept. For the convenience of model development for level of safety service, the factors are categorized major contributing factors, minor contributing factors and traffic characteristics.