Design diagrams for road infrastructure elements

In this paper, the details for the design of road infrastructure elements, including their reliability are provided. This design is based on travel time, its uncertainty, and associated generalized costs of the road user. The paper presents the methodology developed by Bernard and Axhausen (2007), which deals with this approach. It allows the construction of the design diagrams to represent annual generalized costs of the road user for relevant values of volume and traffic flow compositions. The methodology is evaluated for Swiss motorways in order to examine its applicability for the practical uses. As a result, the scope of the methodology is observed to be limited in the current formulation because of the behavior of schedule delay costs of the road user.