Laboratoire de Génie Informatique et d’Automatique de l’Artois

Ph.D. thesis of Kamel BOUMEDIENE

Traffic management : ramp metering and dynamic speed limits

Starting date: 1 December 2007
Keywords: macroscopic modelling, control, traffic flow, DFC strategy, dynamic speed limits, coordinated control

The highways congestion is a problem which appears in a recurring way and which has a wide economic, environmental and social impact. This problem can be resolved by increasing the highways capacity or by decreasing the traffic demand. These solutions are long to operate and are very expensive. An accessible solution in the shorter run consists in implementing a traffic management system.

In this optics, several actions and control measures were developed to improve the efficiency of highways. Among these actions, we can quote the ramp metering control and the dynamic speed limits. The ramp metering consists of a regulation of the vehicles flow wishing to enter on a highway from an on-ramp. We developed the DFC strategy (Différence de Flux Characterisée par une densité désirée). It aims at maintaining on the main road, at the vicinity of the on-ramp, a density lower than a target beforehand determined by means of simulations. This new strategy was compared with the existing strategies such as ALINEA and PI-ALINEA. The DFC strategy presents the interest not to generate oscillatory phenomena in the trajectories of flow and not to require parameters to be adjusted.

The dynamic speed limits imposes on several sections of the main road a speed limit which depends on traffic conditions. The objective is to avoid the congestion at a downstream bottleneck. We proposed several strategies of dynamic speed limits. They use quite the METANET model of traffic. Two of the proposed methods exploit the model METANET anticipation term and the third is based on the flow.

Finally, the various strategies of dynamic speed limits were used in coordination with the DFC ramp metering. The coordination allows to obtain the results better than ramp metering used only or dynamic speed limits used only.

Involved research themes:

No partner is associated with this element.


Defense took place the 15/09/2011 pm30 14:00 Prestige room - FSA - Béthune


  • Président Michel FLIESS Ecole polytechnique
  • Rapporteur Dimitri LEFEBVRE Université Le Havre
  • Examinateur Saïd MAMMAR Université d'Evry
  • Examinateur Hassane ABOUAISSA Université d'Artois