主動運輸有利於身心健康、交通、社會上各方面的發展，因此各國積極推動民眾使用。雖然倡議主動運輸具有許多好處，但若無合適的交通環境，則將會面臨道路上的危險狀況，而成為易受傷害的族群，政策的推廣就變得沒有意義。因此本研究目標為探討影響臺灣的行人及自行車的肇事嚴重程度之因素。
過去臺灣針對行人及自行車的事故研究，多忽略整體數據及個體差異造成的異質性帶來的影響，為解決異質性問題，以潛在類別分析法將數據分群後，利用多項式羅吉特模型及具有隨機效果的隨機參數模型進行事故的分析，以彌補研究空缺。本研究使用2016年至2020年的交通事故資料，利用潛在類別模型將行人及自行車的整體數據分成三群，再將整體及分群的數據進行多項式羅吉特模型及隨機參數模型進行分析。
綜合多項式羅吉特模型及隨機參數模型結果，關於行人傷害嚴重程度的估計結果，發現會增加行人發生傷亡事故可能性的變數包括：清晨或黃昏、晚上有照明、晚上無照明、女性及65歲以上的行人，會降低行人發生傷亡事故可能性的變數包括：雨天、一般號誌附設行人專用號誌、閃光號誌、無號誌、第一當事者、25歲以下的行人。關於自行車傷害嚴重程度的估計結果，發現會增加自行車發生傷亡事故可能性的變數包括：夜間有照明、閃光號誌、女性、飲酒及65歲以上的自行車使用者，會降低自行車發生傷亡事故可能性的變數包括，包括：陰天、雨天、第一當事者、25歲以下的自行車使用者。
綜合上述研究結果可作為提供改善行人及自行車的交通安全之依據，根據研究結果我們建議：針對高龄駕駛人再教育訓練及加強管理；對於飲酒上路的民眾加重罰金；在光線不夠明亮時，行人可穿戴較明亮的衣物或反光手環、自行車使用者可將反光條貼於車上或強制自行車車燈保持開啟；對於號誌不明確的號誌路口應減速接近路口小心行駛、在行人事故較多的路口可增設行人專用號誌，以增加主動運輸的用路安全。

Active transportation is beneficial to health, transportation, and social development. Without safety environment, people will become vulnerable road users. Therefore, this study aims to investigate the factors that affect the severity of pedestrian and bicycle accidents in Taiwan.
The past research ignored the influence of heterogeneity in the data and individual differences. This study uses the traffic accident data from 2016 to 2020, used latent class method to divide the overall data into three groups, and then analyzes the overall and clustered data with a multinomial Logit model(MNL) and a random parameter(RP) model.
Combining the results of the MNL and RP model to estimate the severity of pedestrian injuries, it is found that the variables that increase the probability of pedestrian casualties include: dusky light, female and older over 65 years old. Estimated results of bicycle injury severity estimates found that variables that increase the probability of bicycle injuries include: Light at night, flashing signs, female, drunk driving, and older over 65 years old.
Based on the above research results, we make the following recommendations. Re-education for the older. Increased fines for drunk driving. When the light isn't bright enough, pedestrians and cyclists can wear brighter clothing or stick reflective strips on their bikes and keep bicycle lights open. Normal sign with pedestrian signal can be added at intersections with more pedestrian accidents to increase road safety for active transport user.

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