Evolving lane merge traffic behaviour simulations via a macroscopic objective function and a machine learning system trained through bootstrapped human judgement

摘要

Multi-agent based traffic simulation models have become increasingly important in simulating, studying and analysing traffic behaviours due to their ability to model more sophisticated behaviours of traffic by codifying simple rules into agents. However, such models require selection of appropriate rules and tuning of parameters for the selected rules. This process demands extensive resources if to be done manually. Further, high complexity models (in terms of number of rules and parameters) require a large computational cost to run, imposing scalability problems. In this work, four simple rules are introduced by reformulating existing concepts in the literature in order to simulate the self-organising behaviour of traffic where two lanes form into one and when two types of vehicles (cars and trucks) are present. The optimal rule and parameter combinations are explored via an evolutionary framework to overcome the resource demanding nature of the process. Two forms of objective functions - 1) a macroscopic objective function which focuses on macroscopic properties of traffic 2) a machine learning system trained based on human judgement concerning microscopic interaction of traffic - are studied in order to evolve low complexity and high fidelity traffic simulations. The differences in the rule sets evolved by the two objective functions are discussed highlighting the importance of selecting an appropriate objective function based on the simulation requirements and available resources. Finally, the change of the rule distribution as a function of generation in the evolutionary process is investigated in order to understand the complexity change in the simulations as a function of rule count as simulations are evolving towards high fidelity. This provides an abstract understanding of the relationship between complexity and fidelity in multi-agent based simulations concerning the particular problem of simulation of lane merge traffic.