Evaluation Research Of Urban Road Network In The Central City Zone Of Hohhot

Urban road network is the city's skeleton,which directly affect the city's land use.It fundamentally determines the layout of the bus lines and affects the convenience of residents travel.Once the urban road network is formed,it is difficult to transform.It is necessary to study the current situation and evaluation of the road network in the central urban area of Hohhot.It has guiding significance to optimize the road network planning scheme and solve the urban traffic problem.In the past,the evaluation of urban road network requires a lot of manpower,financial and material resources.The manual measurement and statistics are carried out in the field.The cost is high,the period is long and the road network structure could not be collected and analyzed in time.In this study,the road network of Hohhot city was used as the research object.The remote sensing(RS)images were used to collect the information of the road network,and the relevant data were processed by Arc GIS 10.2.The road length and width of the central urban area of Hohhot were extracted and road network database was established in Hohhot central district.By analyzing the characteristics of the road and comparing it with the "normative",the existing problems of road network were analyzed and the solutions were put forward.Then,the fuzzy comprehensive evaluation method was used to evaluate the road network of Hohhot central district.The main results are as follows:(1)The total length of the road network in Hohhot central district is 1561 km,the road network density is 2.8 km/km~2,the road network area rate is 9.46%,the per capita road area is 20.63 m~2/person and the grade proportion of road network is 1: 2: 2: 5 in the central region of the city.In contrast the road network density is 5.76 km/km~2,the road network area rate is 20.00 %,and the grade proportion of road network is 1: 3: 3: 6 in the core region.The road network indicators are generally low in central region.The trunk road density and branch road density are relatively low in the core area.(2)The road network layout in Hohhot central district is hybrid road network of the "square format + ring radial".The structure of trunk road network is "two ring,eight vertical,eleven horizontal" within the scope of the central district.(3)The grade proportion of road network is unreasonable in center district of Hohhot compared with specification.The evaluation result of road network is also unreasonable.The ratio of secondary road and branch road was significantly lower.Existing problems and countermeasures are as follows:(1)Improve the length and area of the road,especially the length of secondary road and branch road.Demolished through the demolition,opening internal roads in some large residential area and increase the three-dimensional cross to improve the road area and length in the second ring.Outside the second ring it is recommended to directly increase the road area and length in the follow-up planning and construction,especially to improve road area and length ratio of the secondary road and branch road because the main roads is new construction road and there are more open space outside the second ring.(2)Improve the road network structure.At present the road network structure is imperfect in the central region of Hohhot.The expressway basically forms a “ring+radial” structure which only relieves the demand of circular traffic and does not solve the long-distance traffic demand in the second ring.It is proposed to make all-round interchange of the roads within the second ring road and connect with the existing circular expressway to form a fast road network similar to the shape "?" or "?" to solve the traffic required within the ring.There is a single link between the central city and the surrounding group at present,which forms the traffic bottleneck between the delegation and the central city.It is suggested to increase the second tie line between the delegation and the central city to alleviate the current "bottleneck" problems.(3)Accelerate the construction of rail transit,urban bus routes and public bicycle parking,formation integrated transport system,and share road traffic pressure.Finally,the main conclusions of this study were summarized,the shortcomings were analyzed in order to provide the basis for further research.