由於臺灣地區之旅運者相當依賴使用私人運具，不僅使得旅運者在有限的道路容量下會產生交通壅塞問題，對於環境亦會造成汙染。鼓勵旅運者多使用公共運輸無疑是最有效的改善對策之一。此外，由於公共運輸服務水準及使用私人運具的便利程度，會因旅運者居住地區而異，因此，本研究在分析旅運者之運具選擇行為時，先依據旅運者居住地區分為 3群，並分別建立該地區之運具選擇模式。同時利用可分析異質性的混合羅吉特模式加以模化。推估結果顯示，分群所建立的混合羅吉特模式皆顯著優於多項羅吉特模式，表示運具選擇行為確實存在個體異質性。最後，進行彈性分析及市場占有率預測，以了解提昇公共運輸使用率的關鍵因素，並提出對應的市場行銷及改善策略。

Due to the high dependency on private vehicles of travellers in Taiwan, the traffic conditions in many surface roadway systems are rather congested with serious problems of energy consumption and emissions. To promote the usage of public transportation is undoubtedly the of the most effective countermeasures. Additionally, to acknowledge the roneemarkably different service levels of public transportation and different convenient levels in using private vehicles in different residential areas, significant differences must exist in their mode choice preferences and decisions. Thus, the heterogeneity of mode choice behaviors should be analyzed. Accordingly, this study separately develops the mode choice models for those travellers living in the districts/townships with different levels of population density by using mixed logit models (MXL). The estimation results show that MXL models for three groups perform significantly better than multinomial logit models in terms of likelihood ratio tests, suggesting the existence of heterogeneity in mode choice behaviors. Finally, elasticity analysis and marketing share prediction are conducted to identify the key factors for promoting public transportation. Corresponding marketing and improvement strategies for public transportation are then proposed accordingly.