Freeway ramp metering based on genetic algorithm optimization

Contraposing the complexity of a ramp control problem, we propose a method of proportional plus integral (PI) control and genetic algorithm optimization for ramp metering in this paper. Firstly, we build a cell transmission model (CTM) for freeway traffic. After that, we design several ramp controllers based upon CTM and feedback control method, and give the optimization process of a genetic algorithm in detail for optimizing the PI parameters. Finally, we simulate the ramp controllers by computer. Simulation reveals that the ramp metering controllers based on genetic algorithm optimization are of good performance. This control method can stabilize traffic flow as well as improve traffic situations.