简介：Trafficruleisakeyfactoraffectingtrafficflowandsafety.Wedevelopourmodels,includingthecellularautomatatrafficflowmodelaswellasthelinearregressionone,aimingatcalculatingtrafficflowandevaluatingsafetyconditionswithvariedtrafficrules.Then,wethoroughlyinvestigatefourtypesofpathsinafreeway,namelytwostraightlanes,threestraightlanes,ramps,androundaboutsascasestudiesanddiscussthedifferenttrafficrulesascomparison.Theresultsdemonstratethat“Keep-Right-Except-To-Pass”ruleisnotaseffectiveasthefreeruleinpromotingtrafficflow;however,thisruleensuressafetyfordriversbetterthanthefreerule.Additionally,anewtrafficrule,whichsetsdifferentpostedspeedlimitsforadjacentlanes,isproposedtopromotebettertrafficflowwithsafetyrequirementssatisfied.Furthermore,weapplyeffectiverulesandalternatives,leftdrivingnormsaswellasintelligentsystemasextensionandobtainbetterresults.Finally,model’ssensitivityanalysisregardingtoprobabilityofdeceleratingandpostedspeedlimitsprovesthestabilityofourresults.