公車專用道實施對公車服務水準與載客量之影響－－以臺北市為例

An Assessment of Effect Exclusive Bus Lanes on Buses' Level of Service and Ridership- Taking Taipei as an Example

台北市政府交通局為求有效改善公車營運的實質環境，故沿用過去兩條逆向公車專用道之成功經驗，於民國八十五年一月到八月間陸續完成七條幹道之公車專用道設施。本研究之目的係分析此項計畫性變革措施是否對於台北市公車服務水準與載客量造成顯著性的正面影響。本研究蒐集相關研究資料，並應用統計程序，檢定實施公車專用道前後上述兩類變項是否有顯著性差異。結果發現(1)公車專用道的實施在效率性及便利性之服務水準上有顯著的正面效益；但安全性方面在實施初期卻有顯著負面效果，但在實施一年後，公車專用道上之肇事率顯著低於全體公車平均肇事率。此外，除部份路段小汽車旅行速率有些微降低趨勢，總體而言各路段小汽車的平均旅行速率呈增加趨勢，且有統計上的顯著意義。(2)對於公車載客量的影響，經本研究考量時間數列變化，應用ARIMA方法先修正事前資料後再與事後資料比較，顯示公車載客量有顯著增加。

Taipei is facing serious traffic congestion problem. In order toincrease the bus ridership, the two contra-flow bus lanes had been implementedon two major arterial streets since February 1990. Department of Transportation,Taipei City Government had imposed another seven exclusive bus lanes fromJanuary to August in 1996. This study intend to assess the effect of the buspriority strategy on buses' level of service and ridership. We collected (1)secondary hand data, (2)questionnaire survey data and (3)field investigationdata. This study used the statistical test procedure to draw an appropriateconclusion from sample data for the difference between two population parameters(before and after). The ARIMA (Auto-regressive integrate moving average) method,a time series model, also be developed for evaluating whether the bus ridershipis increased or not. The results showed that (1) "efficiency" and"convenience" - two factors of buses' level of service - got positive effect,"safety" got negative effect in initial stage and got positive effect after oneyear, (2) the ridership of buses showed significantly increased after the buslanes implemented.