Abstract: There exists randomicity in the crossing and overtaking behaviors of trains on single-track railways. The number and patterns ofthe crossing and overtakingoftrains in various operation conditions are studied by probabilistic analysis. The relationships between the number of arrival and departure tracks and the crossingorovertakingnumber and patterns are obtained. The main factors thathave a direct influence on the number of tracks is found out, and the variation rules of these factors versus the track number are presented. The results obtained have been used to analyze the number of tracks on Chongqing-Huaihua railway.