IDENTIFICATION OF AT-GRADE INTERSECTIONS CHARACTERISTICS FOR DEFINING BASIC INPUTS INTO MCA METHODOLOGY

Jan Hradil, Michal Uhlik, Petr Slaby

Last modified: 2017-02-28

Abstract


The article deals with the determination of basic traffic engineering and measurable urban planning criteria needed for a complex assessment of intersections. The current assessment method of intersections in accordance with applicable regulations is virtually bound on suitable capacities but each intersection may also be described by means of a set of clearly expressed values; based on these values, its suitability for given conditions and thus also
the utility value of a proposed design solution may be determined by means of the Multi-Criteria Assessment (MCA) application. The basic criteria defining each at-grade intersection were the mean delay time, the safety index, environmental impacts (particularly CO2, NOX and
PM), noise impacts on the surroundings, construction and operating costs. In this context, it is obvious that it is also necessary to define the input parameters of a respective intersection on the basis of which the above values of the criteria will be defined. The article primarily describes the dependences between the above criteria and input traffic volumes for basic shapes of intersections. In the first phase, basic layout types of intersections were modelled in the form of a set of basic shapes of intersections – in the future, we plan to extend this set by multi-lane intersections and intersections with separate turn lanes. The distribution of traffic volumes into individual branches was carried out for several basic combinations. The dependences are elaborated in a clear graphical and tabular form allowing the designer or investor to make a preliminary assessment of different design options of an intersection, particularly in the initial phases of design. It is also possible to use the dependences as an
alternative to computerised assessment in accordance with applicable regulations.

Keywords


multi-criteria assessment, intersection, intersection capacity, environmental impacts, noise impacts

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