At present, the existing thresholds of indexes for bus service level evaluation lack considerations for cities with special conditions. The social conditions, urban size, geographical and topographic features of mountainous middle-small cities are quite different from other cities. In this study, the evaluation indexes reflecting the characteristics of mountainous middle-small cities are selected. Besides, the cumulative frequency curve method is used to analyze the frequency distribution of index values, which are used to determine the thresholds of evaluation indexes in line with the characteristics of mountainous middle-small cities. The result of the current study could provide some valuable insights for improving the authenticity and reliability of evaluation results.

CICTP