Traffic engineering and the new German highway capacity manual

Traffic engineering in Germany has a long tradition. The standards for practical application, however, are distributed among a variety of guidelines. These, in many cases, are not up to date. Therefore, in practice, more recent research results are applied by traffic authorities and consultants. To improve this practical application on a more sophisticated background, a manual for traffic quality and capacity on streets and highways is intended to be prepared. A first draft has been worked out by a university institute and is to be published in 1994. This article presents the background for the chapter on highway sections and motorway interchanges for signalized and unsignalized intersections. Pedestrian and public transit facilities are mentioned as well. Special attention is drawn to the most recent research results which are included in the manual. These are delays at intersections under nonstationary conditions, including queue length and distributions (e.g. 95-percentile queue length). For motorways, the lack of a general speed limit in Germany has important impacts on determining measures of effectiveness.