In urban agglomerations, signalized intersections are common. However, in traffic management, safety-focused strategies are often sacrificed for traffic efficiency by allowing simultaneous multiple conflicting movements. We identified this issue by analyzing the most dangerous signalized intersections in several Polish cities. Our research evaluated whether obstructed sight distances between major and minor traffic streams could be a significant problem at these intersections. To achieve this, we employed existing models of visibility analysis related to stopping sight distance. We determined the key parameter for stopping sight distance based on our vehicle speed studies. Tests were conducted using unmanned aerial vehicles over the intersections in the cities under consideration. Subsequently, we adapted available sight distance models to characterize conflicting streams with simultaneous green signals in a signal phase. We distinguished between major movements, including tram, pedestrian, and cyclist traffic, and minor streams, primarily involving turning vehicle movements at the intersection. Through this approach, we analyzed stopping sight distance and found that in about 60% of the cases studied, the obstructed sight distances led to a higher number of traffic incidents in the areas of conflict between major and minor traffic streams. The overall number of traffic incidents was more than 57% higher in areas with obstructed sight distance conditions, with the worst statistics involving incidents with vulnerable road users. This straightforward approach confirmed the findings of many studies that sight distance is one of the most critical factors influencing traffic safety. Based on our research findings, we recommend implementing safe traffic management strategies at intersections with obstructed sight distances, specifically multi-phase signalization. Additionally, due to the often-necessary compromise in phases involving pedestrian and cyclist traffic, we recommend conducting required sight distance analyses for vehicles turning left or right while conflicting with pedestrian or cyclist streams during a shared signal phase. Given the simplicity of the method, further research is needed to refine the approach, possibly by incorporating a stochastic model.


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    Title :

    Impact of visibility on traffic Incidents at signalized intersections –a case study in Polish cities


    Contributors:


    Publication date :

    2025




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    Unknown






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