This paper presents traffic speed models developed on the basis of numerous measurements. In studies of the speed–flow relationships the following research issues were analyzed: impacts of the speed limit, traffic flow, traffic flow composition, and time of day on speed–flow and impacts of qualitative road and roadside features (cross sections, road function, accessibility, intensity of development, roadside pedestrian traffic) on free-flow speed. The research included road sections with numerous constraints of traffic freedom. Such sections include sections of roads through built-up areas (small communities and towns). Regression analysis using generalized multiple regression was the basic tool in investigations. In addition, in analyzing data from speed measurements, the classic form of the logit function for a multiple-valued regression was applied. The analyses showed that even at general and posted speed limits the characteristic traffic flow–speed relations can be identified. The shape of these relations is characteristic of empirical results in which the spread of recorded values is typical for randomness and impacts of local factors. Average speed in traffic flow depends not only on geometric alignment of a road cross section but also on local factors and speed limits. Speed in free-flow traffic is significantly influenced by qualitative road and roadside characteristics. Most important of these factors are type of cross section, intensity of roadside development, and accessibility of the road.


    Access

    Download

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Influence of Various Restrictions on Speed–Flow Models


    Additional title:

    Transportation Research Record


    Contributors:


    Publication date :

    2009-01-01




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English



    Influence of Various Restrictions on Speed-Flow Models

    Şahin, Ismail | Online Contents | 2009


    Checking speed restrictions

    Engineering Index Backfile | 1935


    Fluid Flow Through Restrictions

    Greenland, L.S. | Emerald Group Publishing | 1943


    Fluid Flow Through Restrictions

    Emerald Group Publishing | 1943