Weaving Areas between Junctions on Freeways

Problem Statement

In metropolitan areas with closely spaced intersections, as well as when two freeways overlap, there is often a need to arrange long weaving sections between adjacent intersections. These large weaving sections typically have four or more lanes and an addition or subtraction of one or more lanes at their beginning and end. According to the previous guidelines, such weaving sections can be defined as weaving sections of four types, V 1, V 2, V 3, and V 4, which can be used to represent the basic forms of weaving maneuvers. For the traffic engineering design of such design situations, no suitable procedures are available in the German regulations so far.


The aim of the research project is to expand the set of rules for the design and traffic engineering dimensioning of freeways to include procedures and guidance for the design and evaluation of major weaving sections between intersections.


Within the scope of the project, weaving sections with different structural and traffic-related boundary conditions are analyzed with regard to traffic flow and traffic safety, and the data basis is expanded to include boundary conditions that are not or not sufficiently observed by means of microscopic traffic flow simulations. Furthermore, the application of the macroscopic software tool "German FREEVAL" will be reviewed and the fields of application of microscopic simulation as an alternative method for the evaluation of weaving sections will be analyzed.

Based on the findings on traffic flow and accidents, recommendations for the design, traffic engineering dimensioning as well as the design of signposting, lane marking, traffic regulation and, if necessary, traffic control of weaving sections between junctions on freeways will be developed for adoption in the RAA, the HBS and the RWBA. An analytical procedure for the traffic engineering design of weaving sections will be developed for the update of the HBS. Furthermore, it is shown within which application limits the developed analytical procedure can be used for weaving sections and in which cases the microscopic traffic flow simulation or the macroscopic modeling with FREEVAL can be applied.