節能減碳不僅為世界各國的經濟願景，更是社會責任，因此，公部門致力於提升公共運輸整體能量與品質，並朝著低碳減污之永續綠運輸系統的方向邁進，如何有效推動公共運輸之使用遂成為各國相關政策發展主軸。有鑑於此，本文運用「分量迴歸法」（quantile regression），透析汽車客運路線特性與班次對高、中、低運量路線的邊際影響，藉以提供擬訂促進公共運輸運量政策之參考。實證結果顯示，班次與路線特性為影響運量高低之重要因素，班次對高運量路線提升客運量之效果較低運量路線高，且兩者呈非線性關聯。在路線特性方面，捷運與臺鐵之旅客人次增加，將有助提升汽車客運之搭乘人數。

Energy conservation and carbon reduction are not only important international economic issues but also important social issues. The policies of the public sector aim to improve both the capacity and quality of public transportation services and build a sustainable green transportation system. We use quantile regression analysis to investigate the impact of low-, medium-, and high-capacity routes on passenger volume in this paper. The research shows a nonlinear relationship between the number of bus runs and passenger volume. Furthermore, the effect of bus runs on the number of passengers is stronger in high-capacity routes than it is in low-capacity routes. Additionally, an increase in railway or MRT passengers is also expected to increase the number of bus passengers.