This chapter aims at describing and clarifying the concept of infrastructure capacity as it has been used in different countries and modes in order to support infrastructural planning, design, and operational activities. Section 2 surveys these concepts and the extensive literature on methods that have been developed to estimate road capacity - both physical and "economic" - in the context of a level-of-service notion. It notes the practical advances in traffic design and operations generated by these capacity assessment methods (largely derived from the U.S. Highway Capacity Manual) as well as the pressures for road investments such capacity estimation methods have created. Section 3 describes the emerging variety of policies and measures that expand the capacity of different modes of existing infrastructure. It also surveys the broad range of policies and measures which manipulate the demand for transport capacity. Finally, some analytical and policy inferences drawn from this brief survey of the concept, measurement, and augmentation of infrastructure capacity conclude the chapter.
Abstract