Critical gap is a crucial factor for capacity estimation and safety evaluation at uncontrolled mid-block median openings (MBMOs). The U-turning vehicle makes a U-turn when a sufficient gap between two fast-moving vehicles is available in the approaching through traffic (ATT) stream. Even though, worldwide, temporal gaps are extensively used, the spatial gap is an important parameter that significantly affects minor street vehicles’ safety (U-turning vehicles in this study). The present research, undertaken in India, focuses on estimating the temporal and spatial critical gap of U-turning vehicles at uncontrolled MBMOs. The collected data were analyzed for six different types of U-turning vehicles at varying approaching through traffic volume (ATTV). For critical gap estimation, four different critical gap estimation techniques, namely, modified Raff method (MRM), Ashworth method, binary logit model (BLM) method, and occupancy time (OT) method were employed, separately. From the analysis, temporal and spatial critical gaps were observed to vary between different types of vehicle, and it was also observed to vary with ATTV. The critical gap values of this study were found to be smaller than the critical values reported in developed countries, signifying the aggressive driving nature of drivers in developing countries. A detailed appraisal of the different critical gap estimation methods has been carried out. From this analysis, the OT method was found to provide the closest critical gap values with the published literature compared with other methods. Lastly, the findings from the present study will be useful for capacity estimation and safety evaluation at MBMO.


    Access

    Download

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Comparative Appraisal of Critical Gap Estimation Techniques in the Context of U-turning Vehicles


    Additional title:

    Transportation Research Record




    Publication date :

    2021-08-08




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English




    Transport Appraisal in a Policy Context

    Mackie, P. / Nellthorp, J. / Interdisciplinary Centre for Comparative Research in the Social Sciences | British Library Conference Proceedings | 2003


    The GER - A Critical Appraisal

    Pember, G. | British Library Online Contents | 1993


    Turning vehicles into generators

    Carney,D. | Automotive engineering | 2004


    THE GLIDER, A CRITICAL APPRAISAL

    Arcier, A Francis | SAE Technical Papers | 1944