根據內政部警政署統計通報得知，近六年臺灣A1類道路交通事故肇事原因均以「酒醉(後)駕駛失控」為首，顯示酒駕肇事往往釀成嚴重傷亡。本研究以計劃行為理論與風險感認、自我效能構念進行民眾使用代理駕駛行為意向的探討，並根據內政部警政署統計酒駕死亡人數資料選擇高雄市、臺中市、桃園縣做為調查地點，最後研究共回收1,088份有效問卷。透過敘述性統計、獨立樣本t檢定、結構方程模式及多樣本結構方程模式分析，結果顯示態度、主觀規範、知覺行為控制、風險感認對於行為意向有顯著正向影響；自我效能對於行為意向則有顯著負向影響。在多樣本結構方程模式分析中，測量恆等性結果符合指標，顯示性別與年齡特性對於模式部分並不具有調節效果、階層調節迴歸顯示顯示性別與年齡特性對於模式斜率項具有調節效果。;According to National Police Agency statistics that in recent 6 years Taiwan A1 class traffic accident cause of the “driving under the influence” most. It means driving under the influence tend to make heavy casualties. This study based on the theory of planned behavior, risk perception and self-efficacy factors to investigate the people’s behavior intention about using designated driver service. According to National Police Agency statistic, select Kaohsiung, Taichung and Taoyuan cities to be the sampling locations. A total of 1088 questionnaires are fully completed. The data was analyzed by descriptive statistics, reliability and validity analysis, t-test and structural equation modeling. The results showed that “attitude”, “subjective norm”, “perceived behavior control” and “risk perception” factors have significant positive effect to behavior intention, “self-efficacy” factor has significant negative effect to behavior intention. In the multi-group structural equation modeling, the results showed that study model can pass the measurement invariance test. In this study, the structure has no moderator effect about different ages and genders.