How to measure capabilities within corridors?

Traditional methods of measuring the capacities of infrastructures are usually based on indicators like passenger car units (PCU). It is quite clear that these methods of capacity evaluation (categories of roads, calculation procedures, capacity limits, e.g. defined in the HCM – Highway Capacity Manual) cannot be used to picture the intermodality of the traffic system. The first step has to include the intermodality (modal split) in the cross section of a road (pedestrians, bicycles, public transport, private vehicles), and in a further step it is necessary to account for all alternatives within the corridor, like parallel routed railways or public transport lines, to reach an intermodal point of view. Finally it is also necessary to include the effects on the settlement structure. Beside intermodality, any new method also has to consider cost effectiveness, a comprehensive consideration of feedbacks in the traffic system, as well as compatibility to CBA. As a result it is necessary to find new indicators (instead of car units) to define passenger and freight flows. There are guidelines in progress auditing transport operations and infrastructure conditions of roadways. A revision of these guidelines aims to integrate different modes of transport by changing the key-indicators (e.g. incline, curviness, roadway width, capacity utilisation) and to use a system approach which includes indicators like modal split, car occupancy or utilised capacity of lorries. The procedure presented in this paper can be seen as one building block to meet the demands of future assessments within corridors.