关键词: 过境环路, 规划理论, 合理半径

Abstract: This paper is based on the research of the road net structure forming by radiation and ring.Firstly, it elaborates the relations between city transit circular road and city development, transportation requirements, development of products and coordination of landscapes in a new turn of city construction.Secondly, it acquires the mathematical model about the relation between circular route's location and the transportation origin-destination.At last, it deals with the principle of the defining of reasonable radius.So it makes plan of the circular road guided by the transportation requirements and combines with the development of city, forming a graceful building space in the belt between urban district and suburbs.

Key words: transit ring road, planning theory, reasonable radius