An interpretation of speed-flow-concentration relationships using catastrophe theory

The occurence of gaps in freeway operations data, for example in flow-concentration plots, and the accompanying jumps in the behavior of some of the variables, have been observed in many data sets. Conventional representations of speed-flow-concentration relationships do not address those jumps, much less explain why the jumps occur at different values of the variables in different data sets. Catastrophe theory provides a way to understand that …