New model for variable speed limits

Abstract

Traffic flow models play an irreplaceable role in the design and evaluation of variable speed limit (VSL) controllers. All existing models for incorporating VSL effects are based on modifications of the steady-state fundamental diagram. A new model is proposed: it is derived from driver behaviors with VSL control. The proposed model is validated with simulated data from VISSIM microscopic models and is compared with an existing macroscopic model modified to account for VSL. The proposed model is shown to have more accurate descriptions of the transient effects of VSL than the existing model, which takes into account only the steady-state effects of speed control inputs.