German roads with intermediate cross-sections: Operations, flow and capacities

Abstract

Intermediate types of cross-sections for roads outside built-up areas are defined as types to classify between typical two-lane two-way roads and roads having full-size dual-carriageways. Often discussed are whether the quality of service on rural roads has become poor because of increased traffic loads and, in cases where these loads are not considered to be heavy enough, whether to provide standard cross-sections with dual-carriageways (motorways). The types of road having intermediate cross-sections can be categorized therefore as upgraded (widened) rural roads or as downgraded dual-carriageways (narrow or stripped). It is obvious that these types provide different capacities and especially different qualities of service. Summed-up results from several research projects using empirical data, theoretical valuation and microscopic simulation techniques are given concerning aspects of traffic operations, flows and capacities for different road types. Additionally, the criteria for provision, especially in German guidelines, of such kinds of roads are presented.