「需求反應式公共運輸服務」(Demand Responsive Transit Services, DRTS)能於運輸需求產生之同時,適時地提供運輸之供給服務,其能提升乘載率並降低業者之營運成本,同時提高運輸服務品質與績效,提供更具有競爭力之公共運輸服務。DRTS具有地域性強之特性,服務型態與營運服務等細節皆需配合所在地區進行規劃及設計;因此,為提供一有效能之DRTS運輸服務,本研究同時考量營運者及使用者之總成本,利用分析性數學模式,探究固定班次之主幹線運輸,提供彈性彎繞服務,並整合完全彈性運輸服務之混合車隊DRTS系統。研究中以系統總成本最小為目標,對於彎繞距離以及車隊組成規模進行最佳化之設計。 研究中並以數值實例驗證模式之適用性,其結果顯示,在服務區域長為16公里、寬為9公里,總需求人數為125人情形下,最佳彎繞長度為2.04公里、完全彈性服務區則為2.46公里,固定班次服務之最佳化車隊規模為5輛中型巴士,完全彈性服務則需6輛九人座巴士。模式之參數敏感度分析顯示該決策變數受服務範圍長、服務範圍寬、支線需求之影響相當顯著,行人步行速度、主幹線車輛車公里成本等則較不敏感。透過本研究建立之模式及分析結果,可在規劃階段提供DRTS最佳化設計之參考。
Demand Responsive Transport Services (DRTS) is an advanced, user-oriented form of public transport characterized by flexible routing and scheduling of small/medium vehicles operating in shared-ride mode between pick-up and drop-off locations according to passenger’s needs. DRTS can provide more affordable and convenient transport service and can reduce the vacancy rate and raise the passenger load-factors. However, DRTS is a new transport service in Taiwan and type of service of DRTS needs to be designed based on the service area’s features. Therefore, this study developed a mathematical model to analyze optimized design of DRTS while minimum total system cost is considered as the objective function. The system provided a scheduled bus service in main line which allowed deviate from the fixed route to service some of the branch line in the area and the rest of the area is served by flexible route DRTS. In this mixed fleet system, the optimal length of route deviation and fleet size are the decision variables. Moreover, numerical examples are used to verify the applicability of this model. The example shows that, when the length of service area is 16 km and width is 9 km,, the optimal length of route deviation is 2.04 km for demand density of 125 trips per hour. Optimal fleet size of scheduled bus service is five mini-buses and optimal fleet size of DRTS is six. Sensitive analysis is also conducted to evaluate the effects of important parameters on the system design. The length and width of service area and demand density of branch line are most sensitive to the total cost. And vehicle kilometers cost and walking speed are least sensitive to the total cost. Results of this study could be used as a guideline for design and planning of the demand responsive transit system.