Variable Speed Limit Control with Dynamic Location of Message Signs for the Internet-of-Vehicles Environment

Abstract

The control position for traditional variable speed limits (VSL) is generally fixed. However, when congested traffic flow reaches the variable message sign, the effect of VSL on easing congestion will be reduced. It is, therefore, necessary to dynamically set the location of the variable message sign while implementing dynamic traffic control. Combined with the emerging Internet of Vehicles environment, this paper designs a variable-length cell transmission model to describe the uneven uniformity of traffic and to calculate the speed limits position of dynamic VSL. Then combined with the VSL control, an objective optimization function is established, with the travel time being the object. By numerical analysis and simulation, the sensitivity of the dynamic transmission model is verified under different traffic conditions. The results show that the proposed model can change the length of the cell and better describe the uneven distribution of the crowded tuple. The location of variable message signs can be set dynamically, and it can significantly alleviate the congested area. In addition, the new dynamic variable message sign control method can shorten travel times and improve traffic efficiency.