Abstract: In this paper, predicted the time saving of traffic according to the traffic property of the automobiles passing the grade crossing. Based on the method of the moving investment-pay time estimated the ecconomic loss for twenty six typical grade crossings investigated in five proviuces of China and obtanied the equations of the regression of ecconomic efficiancy, highway and railway tnaffic volume by using the method of gradual regression analysis. These equations are the setting condition of highway and railway Cross-over.