关键词: 交通工程；对外交通；&ldquo, 双四阶段&rdquo, 法；交通分区

Abstract:

In order to overcome the disadvantages of the existing method，a method called“dual fourstage”is put forward to analyze external traffic demand in city area according to the features of external traffic．The proposed method is carried out by two steps，and in the first step the city area is regarded as a whole traffic zone and the“four stage”method of regional traffic demand analysis is implemented to obtain the total generation volume of internal- external trips of city area and traffic volume on both directions of each arterial highways through the city on planning years；In the second step the planning area of city is divided into several parts as internal traffic zones，and the external traffic zones are set at the intersections of highways and cordon line，then a second round of“four stages”method is applied to obtain the trip generation and distribution of internal-external trips and external-external trips for internal traffic zones and external traffic zones on planning years．The practical application of the analysis of external traffic demand for comprehensive traffic planning of Zhenjiang City shows that the presented method combines the advantages of influence area method and cordon line method，and overcomes disadvantages of the both methods，thus the analysis results are more consistent with the real situation．

Key words: traffic engineering；external traffic；&ldquo, dual four-stage&rdquo, method；traffic zones