Study on the traffic flow under keep-right-except-to-pass rule based on cellular automata model

In those countries where driving automobiles on the right is the rule, multi-lane freeways often employ the keep-right-except-to-pass rule. To study the influence of this rule on the traffic flow, we improve the existing cellular automata model and take into account the velocity differences and random factors about changing lanes. Then a new kind of cellular automata model is proposed and used to assess the performance of this rule in terms of traffic flow, safety and posted speed limit. Simulations give us vivid figures, showing effects of density of vehicles and speed limit on traffic flow under that rule.