Turbo roundabouts, emerging as a solution to conventional multilane roundabouts’ safety and operations concerns, are prevalent in Europe and are still new to North America. However, few studies and guidelines on intersection sight distance (ISD) requirements exist. This paper focuses on the basic turbo roundabouts, examines the circulatory roadway and approach design features, and develops ISD models with North American practices. The ISD requirements were identified for the vehicle approaching and entering the roundabout, which conflicts with the circulating vehicle in the circulatory roadways, and the entering vehicle at the upstream entry approach. Analytical models were developed to identify the required lateral clearance at the central island and clear sight triangles at the roundabout quadrants to satisfy the required ISD. The analyses were completed for four typical sizes of basic turbo roundabouts per Dutch design criteria. The design guidelines are provided for the required lateral clearance at the central island and the required clear sight triangles at the roundabout quadrants. They would be beneficial in establishing landscaping restrictions and determining the roadway right of way and property impacts at the intersections during the roadway planning stage.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Intersection Sight Distance Requirements for Basic Turbo Roundabouts


    Additional title:

    J. Transp. Eng., Part A: Systems


    Contributors:


    Publication date :

    2023-02-01




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English






    Turbo Roundabouts

    Fortuijn, Lambertus G. H. | Transportation Research Record | 2009


    Turbo Roundabouts

    Fortuijn, Lambertus G. H. | Transportation Research Record | 2009


    Performance Evaluation of Basic Turbo Roundabouts as an Alternative to Conventional Double-Lane Roundabouts

    Elhassy, Zuhair / Abou-Senna, Hatem / Radwan, Essam | Transportation Research Record | 2021