Traffic Organization And Management Research Of Historic District Based On Urban Traffic Network

Ruan Yisan once said，historic district is the memory and connotation of a city. Itis like an old suffering man, standing quietly in the hustle and bustle of modern city. Itlooked firm and persistent but already exhausted in the surrounding of moderncivilization. Historic district has many functions such as tourism, business,transportation and residential area. All kinds of traffic flow interweave here, whichresulting in traffic chaos, and then the historic district becomes the bottleneck ofregional road network. Therefore, it is urgent to relieve the traffic congestion ofhistorical district by optimizing the road network structure as well as intersectioncontrol and management.Although urban traffic organization and management theory has been very mature,yet in this special historic district area, the general urban traffic organization andmanagement theory has been difficult to apply. Because historic district is subjected tothe existing narrow road network system and the pedestrians and non-motorizedvehicles share a larger proportion of the traffic volume. Moreover, there is aconsiderable amount of historic listed buildings in historic district.This paper first conducted a field survey to a number of historic districts in Xi’an,summarized the typical cross section forms and their corresponding trafficcharacteristics of historic districts. And it made mathematical improvements to BPRimpedance model, combining with influencing factors of the road in historic district. Itestablished impedance models which based on internal one-way roads, two-way roadsand peripheral connectivity roads of historic district. It made parameter calibration tothe model by using the matlab program and established a road impedance function based on the features of historic district.Secondly, the survey found that many branch roads are left unused while the mainroads are congested. By analyzing the traffic characteristics of the roads in historicdistrict and the rationality of implementing one-way traffic, this paper proposed theone-way traffic organization of branch road as an effective management measures torelieve the traffic pressure of historic district. It gave the basic procedure to confirmthe direction and improvement method of one-way traffic of road network accordingto the composing ring orientation method. Using the road impedance function ofabove results and making traffic distribution according to the Wardrop first principle,this paper designed an algorithm of traffic assignment model with the aid of affinescaling algorithm and the Matlab software. Finally, it proposed a one-way trafficorganization and optimization solution which took the example of Xi’an XiangziTemple historic district. It back-stepped the OD matrix by Transcad and solvedthe traffic assignment model to make instance analysis, which had shown a morebalanced traffic distribution of historic district road network. Lastly, it presented animprovement scheme considering the smoothness of road network, and made analysisand evaluation on the scheme.Then, aiming at the historic district intersection characteristics of mixed trafficflow and large flow of people, this paper put forward an optimum design method forthe space of intersection motor vehicle, non-motorized vehicle and pedestrian. Itstudied the minimum time for green light of pedestrian and proposed anoptimization scheme of exclusive pedestrian phases. On the basis of pedestrian flow, itdesigned a signal control scheme, proposed the green light for motor vehicle should be"late start and early break" and gave its time calculation formula. Meanwhile, takingnon-motorized vehicle into account, it proposed the green light for non-motorizedvehicle should be "early start and late break" and gave its time calculation formula. Atlast, this paper put forward a traffic space optimization and signal control scheme withthe example of Houzaimen intersection, then made simulation and evaluation for itbased on the vissim and synchro software.Finally, this paper put forward some other suggestions on historic district trafficorganization and management. This research was funded by the National Natural Science Foundation of China.