台灣地區省道與快速道路近年來相關新建工程陸續完工後，現在工程型態從新建或拓寬工程轉為一般性的道路鋪面養護管理為主；因此，如何在有限的養護經費下運用來維持道路的養護品質及行車路面平整度，就成為政府維護單位最重要的挑戰。台灣地區在快速道路養護部分，則是比較少有相關研究可以供參考，本研究即是在此背景上所建立，本研究的目的即是在探討如何編列相關養護經費才可以維持較好的行車舒適性，首先本研究收集快速道路台61線全線交通量、國際糙度指數（IRI）和近十年各路段養護經費，利用敘述統計、集群分析與迴歸分析台61全線之相關狀況。由研究結果顯示，其中以第二區養護工程處的車輛總數、車流量、重車比例遠高於第一區與第五區，代表其道路的承受破壞風險亦高。在全區交通量分析中，其集群為相對重交通量路段主要集中在第二區養護工程處的路段，僅有一個路段位於第一區養護工程處；本研究嘗試以每年投入的經費與本年度及上年度的同路段的IRI的差值比，發現彼此之間並沒有非常強烈關係，但如果將每年投入的經費跟下一個年度的IRI於本年度的IRI差值比(ΔIRI)1，以第二區養護工程處來看則會呈現非常明顯關係，判定係數高達0.7以上，由數據分析也可以發現，如果投入的金額太少的話，其實對IRI的改善並不會有太顯著的改變，這也可以從實務上解釋如果僅是對表面進行銑刨加鋪動作，對於路面平坦度改善應該非常有限，因為平坦度部分需要從幾何線型去做調整才有辦法把平坦度大幅提升，而且每年也必須要投入相當的經費才有辦法維持或提升平坦度，綜合上述各點，本研究的成果應該可以提供公路總局養護快速道路參考使用。;The networks of Provincial Highway and Expressway in Taiwan are almost completed, and new construction projects became few of a few by year. The Maintenance and Rehabilitation (M&R) of the networks is the most important issue for the Directorate General of Highways (DGH), MOTC, Taiwan. Keeping a specific international roughness Index (IRI) to meet the driver requirement is always a concerned by pavement engineers. The study was based on the above background to build up, and the objective of this study is to improve or keep the IRI of the Total line of Expressway No. 61. The K-mean analysis and regression analysis was adopted to analyze traffic volume, IRI, Capital budget from 2008 to 2019 in this study. Based on K-means, the heavier traffic volume sections were mostly located in the Second Maintenance Office, and only one was mostly located in the First Maintenance Office. The study was tried to discover the relationship between IRI and capital budget. Unfortunately, the relationship between IRI and capital budget in the same years was of no significance. The relationship between IRI and the Capital budget of the last year was better than above. The linear relationship between ΔIRI and the Capital budget of the last year in the Second Maintenance Office was the best model of this study, and the explanation coefficient was above 0.7. In addition, the capital budget of M&R should be larger than a specific amount, and it would be helpful to improve IRI. In other words, if the M&R is only focusing on a 3-5 cm thickness surface layer, it would be insufficient to improve IRI. Based on the above, DGH should make up an annual specific budget to M&R, and the IRI of expressway No. 61 would be improved or kept.
