The Geometry Design Method For Access On Low-Grade Road In Urban-Rural Fringe Area

With the development of urbanization, in urban-rural fringe area, the amount and mechanization level of traffic demand increase fast. While traffic planning, construction and management in those areas are weak, which lead to serious traffic safety problems. Low-grade roads usually serve both commuting and daily life, the means of transportation are complex, meanwhile, with the deficiency of safety awareness of the travelers, the traffic safety issues become more serious.As a key means of traffic safety improvement, access management should be used adequately. This paper aims to study on geometry design for access, the basic purpose is to improve the traffic safety level by making reasonable geometry design.With plenty of survey and investigation, the general cognition of traffic situation in low-grade road of urban-rural fringe areas can be drawn. Refer to related research results, consider safety issues, technical economy, space demand and coordination between several accesses, the method of choosing access type can be drawn. With the investigation of traffic demand in different types of land use, the design vehicle for different types of accesses can be got.With geometric measurement for several important accesses, using mathematical statistics, the key indexes for access geometry design can be analyzed. To limit the proportion of serious traffic conflict, decrease the risk of pedestrians and bicycle users and decrease the accident rate, the reasonable design speed for access can be came up. Then the conclusion of how to value the key plane, vertical and cross-sectional geometry design indexes can be drawn. At the same time, the means of improving the deformity access can be got. By analyzing the movement of vehicles, the insurance of sight distance in both general and special situation for access can be got.Use research results above to make geometry design improvement in a access and make traffic simulation with Autoturn, the result show that both the program and the research results are reasonable and they can be used in practice.