Simulation Study on the Keep-Right-Except-to-Pass Rule Model Based on Cellular Automata

We establish two models with Cellular Automaton (CA) to simulate the conditions of multi-lane freeways under the Keep-Right-Except-to-Pass (KRETP) rule and other improved road rules. We establish the Keep-Right-Except-to- Pass (KRETP) model, which takes into consideration human behaviors when simulating the KRETP rule in both light and heavy traffic. In this model we divide drivers into two categories: active drivers and conservative drivers. Results shows that when compared with single-lane stochastic cellular automata (STCA) model, the KRETP model does not show any obvious difference in light traffic. In heavy traffic, the KRETP rule also barely improves traffic flow. When further examined under different traffic conditions, the KRETP shows that lane changing frequency and the possibility of traffic accidents vary directly with traffic flow and inversely with traffic safety.