A new macroscopic model for variable speed limits

Reference:
J.R.D. Frejo, I. Papamichail, M. Papageorgiou, and B. De Schutter, "A new macroscopic model for variable speed limits," Proceedings of the 15th IFAC Symposium on Control in Transportation Systems (CTS 2018), Savona, Italy, pp. 343-348, June 2018.

Abstract:
This paper proposes a new macroscopic model for Variable Speed Limits (VSLs), combining characteristics of previously proposed models, in order to have the capability of modeling different capacities, critical densities, and levels of compliance for links affected by speed limits. Moreover, the effects of VSLs on the fundamental diagram of traffic flow are studied concluding that, at least for the considered stretch of the A12 freeway in The Netherlands, the capacity of a freeway link is decreased (and the critical density is increased) by reducing the value of the corresponding speed limit. Finally, it is shown that the VSL-induced fundamental diagram is not triangular and that the speed limit compliance can be very low if enforcement measures are not applied.