捷運、經濟弱勢與工作可及性－排除性的長期分析

捷運作為全球各大城市重要的大眾運輸工具，除改善地區運輸條件，具有永續運輸的重要功能，更被認為具有避免汽車導向城市及促進運輸公平之作用。在臺灣，臺北地區更是仰賴捷運作為每日通勤的重要大眾運輸工具。然而過往卻鮮少評估捷運建設後活動重分布對公平性的影響。過往運輸公平研究經常與工作可及性（job accessibility）聯繫在一起討論，個人若處於工作可及性弱勢之狀態，因而無法參與有償勞動，被認為對經濟安全、生活質量以及社會總體福利水平產生嚴重影響。Lucas（2012）指出，如果一個人同時處於運輸弱勢（transport disadvantage）及社會弱勢，將導致運輸貧困、難以取得所需服務、就業機會不足及社會排除（social exclusion）。為探究捷運建設後對公平性影響，本研究以臺北地區（包含臺北市與新北市）為研究範圍，以里為單位探討捷運建設後對於排除性的長期影響，採用捷運1996年開始營運後，每五年工作可及性數據和收入中位數建構之剝奪指標，以兩者差距建構排除性指標，衡量地區排除程度。最後透過追蹤資料迴歸分析(panel data analysis)及普通最小平分法釐清捷運系統與排除性之關係。研究結果證實，捷運建設對排除性具顯著影響，捷運站距離跟排除性間呈現正向關係。此外，捷運擴張及短期影響會改善排除性，然而在長時間之間接影響下，24公里至44公里處距離區間之排除性卻相對明顯，尤其以公共運輸工作可及性建構之排除性較他種運具顯著，顯示居住在此範圍的居民更容易到受排除而無法受益於捷運建設。研究結果也證實某些距離區間下，捷運對排除性無影響，且隨著營運時間拉長不顯著區域越明顯，然本研究尚無法釐清捷運對排除性無影響之確切範圍。本研究在學術上彌補捷運影響研究中缺乏對排除性長期影響的考量；實務上有助於都市規劃者與政府在制定運輸政策時，評估長期性的社會影響，俾憑採取適當配合政策，促進城市發展的包容性。

關鍵字

捷運；社會排除；工作可及性；經濟弱勢；追蹤資料迴歸

並列摘要

Transportation-related social exclusion occurs when individuals suffer both transport disadvantages and social disadvantages because they have difficulty obtaining social welfare, public services, and employment opportunities they need. According to the previous studies, launching a metro system has been proved to affect travel costs among locations immediately and geographical distributions of population and employment in the long term. Such effects gradually reshape job accessibility and socioeconomic conditions of an area and eventually exclude economically disadvantaged people. However, there is limited research on metro-induced exclusiveness in the literature. This research explores the long-term impacts of metro infrastructure on social exclusion applying the data from 1996 to 2016 in Taipei, Taiwan. An exclusion index (the difference between job accessibility and deprivation) is proposed to measure the exclusiveness of an area. Then, panel data regression models and OLS models are applied to clarify the associations of proximity to metro stations and social exclusion. The empirical results reveal that developing metro infrastructure did affect the exclusion of economically disadvantaged people from job opportunities in the past 20 years in Taipei. There is a positive correlation between distance to mass rapid transit (MRT) station and exclusion. The MRT network expansion decreased exclusion in the short term. However, the exclusion within the areas of 24 kilometers to 44 kilometers from MRT stations were statistically significant in the long term. Notably, the exclusion measured by public transport systems revealed more significance than that measured by other transport modes. It suggests that people living in these areas would be easily excluded from jobs and resources especially when public transport is their only choice for commuting. The empirical results also suggest that MRT's influence on exclusion became insignificant in certain distances from MRT stations. Nevertheless, these distance intervals are not continuous and therefore this research couldn't conclude whether the MRT's influence on exclusion is limited in a specific distance. The empirical results help people to make up the deficiency of MRT impact research in observing the associations of geographical alterations of job accessibility and socio-economic conditions with the metro system in the long term. The proposed exclusion index also help planners to clarify the role of public transportation in promoting transport equity.