Legend Pattern Calculation for Dynamic Traffic Management Using ILP

To ensure the safety of highway traffic, traffic management systems are used. In the Netherlands, a traffic management system is used consisting of roadside units, which are controlled from traffic centers. The roadside units are capable of showing legends, such as speed limits or directional instructions. Operators are monitoring the road 24/7, and during roadworks or when an incident happens, they can request a measure, e.g., a lane closure. The system then automatically determines the required legend pattern, comprising of directional arrows to lead traffic away from the closed lanes and speed limits on the remaining open lanes. This system is managed by Rijkswaterstaat, which is part of the Dutch ministry of infrastructure and water management. In this paper, integer linear programming is used to determine the legend pattern, based on operator input. The model adheres to the traffic rules used by Rijkswaterstaat. By using a model-based optimization approach, a solution is found which guarantees legend patterns follow the rules, while minimizing the impact on traffic. The model can be easily adapted to tryout different road configurations or alternative rules. Furthermore, a graphical user interface is created for validation of the generated solutions, by the operators from Rijkswaterstaat. This model is also applicable to highways that are not equipped with physical signaling equipment. Therefore, it can be used to control two thirds of the Dutch highway network, where the current system is not implemented.

I. Introduction

Over the past decades, in many countries, highway usage has increased vastly. To ensure that this does not impair safety, traffic management systems (TMSs) are used. Two categories of TMS s are defined in [1]: infrastructure-based and infrastructure-free. Infrastructure-based TMSs make use of infrastructure, such as traffic lights and roadside units (RSU s) to monitor and control traffic. Infrastructure-free TMSs use only vehicle-to-vehicle communication.