Consistent route flows and the condition of proportionality Academic Article uri icon


  • User equilibrium (UE) static deterministic traffic assignments are widely used in travel forecasting 2 practice. Forecasting analyses that are based on route flows are also quite common, even though it 3 is well known that route flows are not unique under the UE conditions, unless additional condition 4 is imposed, such as the condition of proportionality. 5 The purpose of the research described here is to examine the nature and magnitude of the 6 differences in route flows in a practical setting, by applying several assignment tools that are 7 commonly used in practice, as well as a research assignment tool (TAPAS), to a case study based 8 on the network of the Chicago region. Select link analyses from the various solutions are 9 compared with each other, showing that the differences are practically meaningful. 10 The condition of proportionality is evaluated for each solution by itself. The …

publication date

  • January 1, 2010