Abstract:In order to obtain a reasonable initial horizontal alignment scheme for optimization of a new railway line quickly, the procedure of the initial horizontal alignment is divided into two stages: 1) to find a chain-linked fold line fromthe centerline ofthe route selected by aerial surveying alignment, based onwhich a straight-curve-straight initial horizontal alignment is then obtained, 2) to generate the initial horizontal alignment scheme of the new railway line by optimization design. The method proposed in this paper has been successfully applied to“the intelligent CAD system for railway location”.