Abstract
In the second part of the state of the art report "traffic flow models" the so called macroscopic characteristics of traffic flow are discussed. The most important are the intensity, the density and the average speed. These magnitudes are defined in different, but mutually consistent, ways according to whether they concern: a road section and a point of time; a road section and a period; a road sector and a period. The macroscopic characteristics such as performance, journey time, flow and density are also defined. Measures which can be indicated in principle by the relation between traffic concentration and degree of safety are also studied. For abstracts of parts 1, 3 and 4 see IRRD abstracts nos 240606, 240608 and 240609.