STANDARDS OF ROAD CAPACITY AND GEOMETRIC DESIGN IN GERMANY

This paper is concerned with the group of standards for the design of roads and highways outside built-up areas called RAL. The standard RAL-N (N=network) may be used for the quick classification of roads (by their regional importance) to determine the necessary traffic flow conditions. To estimate the capacity and level of service of these types of roads, a set of tables has been elaborated by measurements of traffic flow under real conditions. The relationship of geometrical design and design speed is discussed. The elements of horizontal alignment and vertical alignment are considered, as well as the sequence of the elements of alignment. Three dimensional design is discussed.