本研究係針對先進旅行者資訊系統網站，發展網頁介面目錄選項排列可用性分析模式，並以臺灣地區高速公路即時交通資訊網站為例，說明該模式之分析過程。首先蒐集國道高速公路局即時交通資訊網站網頁伺服器點擊流資料，構建原資訊架構下之連續時間馬可夫鏈使用者網頁瀏覽行為模式，並以平均使用者對話時間為網頁介面目錄選項排列可用性績效主要量化評估指標，不同排列順序之可用性績效，可由連續時間馬可夫鏈模式計算獲得。此外，由於行前交通資訊需求變化具不確定性，透過遺憾準則，可用以決定該網站資訊架構下之一般性目錄選項排列方案。實例分析結果顯示，無論有無改變網頁上目錄選項「即時交通資訊」與「旅行時間計算」之排列順序，其平均使用者對話時間與行前交通資訊需求變化均呈現線性關係。即使該可用性排列順序取決於行前交通資訊需求變化，分析後發現兩目錄選項交換排列順序後之可用性將優於原有排列順序。

The objectives of this study are to develop an interface usability analysis model for menu-item presentation sequence in web-based advanced traveler information systems (ATIS) and to conduct an empirical study of the freeway real-time traffic information website in Taiwan to illustrate the analysis pro- cesses of the model. The clickstream data collected from the web server were used for constructing a continuous time Markov chain (CTMC) model to represent users' web browsing behavior under a sequence of information architecture design. A major quantitative measurement of performance, expected time duration of user session (ETDUS), was estimated by the time-independent state probabilities obtained from CTMC model to show the results of menu-item sequence usability testing. To cope with the uncertain varying demands of pre-trip travel information (PTTI), a common sequence of menu-item alternative was determined by regret criterion. The empirical results indicate that there is a linear relationship between ETDUS and PTTI demands under a specific original as well as exchanged sequence of menu items for two text hyperlinks of real-time traffic information and travel time calculation shown on the relevant web pages. Although the appropriate sequence heavily depends on the variation of PTTI demands, it is found that the exchanged menu-item presentation sequence is better than the original one.