|Abstract: ||摘要:台灣三大都會區(台北、高雄、台中)之主要通勤道路在尖峰時段中所出現車陣大排長龍之狀況已是日益嚴重之問題。政府相關單位雖極力設法改善此一現況,但終究成效不彰,道路擁塞依舊。本研究計畫即是針對以上之問題,考慮在市區道路以尖峰時段擁擠收費之方式來分散通勤者之出發時間並改變通勤者收費前之路徑選擇,進而減少通勤者在通勤道路上擁擠延滯之時間。尤其在市區之道路網中,具有替代性之道路錯綜複雜,通勤者對收費與不收費道路之路徑選擇將會影響收費後之擁擠減少效果。故收費後通勤者行為模式之研究將是政府相關單位考慮是否實施市區道路擁擠收費時之重要參考指標。 由於通勤車輛排隊擁擠之情形最易發生於瓶頸路段,故本研究計畫案將以道路由寬變窄之某一嚴重塞車路段作為收費對象路段。另一方面,因為收費道路與不收費道路在市區之路網中往往具有替代及互補之作用,如何有效預估通勤者在擁擠收費後之路徑選擇行為以及出發分散之均衡狀態乃是導入市區道路擁擠收費前之重要工作。該預估工作所牽涉之變數既多且雜,實難建立一套固定公式來涵蓋所有可能之情況,故本研究計畫擬採運輸規劃中探討及預測運輸需求的總體程序性需求模式中交通指派之步驟,以分析並預估通勤者在市區道路擁擠收費下之路徑選擇與出發分散之均衡行為模式。 本計畫同時應用計畫主持人於1994年所發表之階梯式擁擠收費制做為道路擁擠收費之依據。但由於該收費制之背景假設乃是針對唯一且獨立存在之通勤瓶頸路段,故通勤者無路徑選擇之餘地,僅能改變其原來之出發時刻作為通勤選擇之依據。有鑑於此,本研究計畫擴充階梯式擁擠收費模式中單一瓶頸路段之背景假設為市區路網,以預測具有多路徑特徵的市區路網在實施最佳階梯式擁擠收費前後之通勤者路徑選擇與出發分散的均衡行為模式。發展多路徑擁擠收費模式之目的在於追求路網最大效用,亦即使同一起訖點的各路徑能有符合道路容量比例的車流使用,讓市區路網之車流均勻分配在每一可行的路徑上,改善市區路網在上、下班通勤時段中某些路段特別擁擠,其他路段卻未能充分發揮其設計上疏導車流之功能。本研究計畫期能將理論活用於實務中,並促使最佳階梯式擁擠收費結構能適用於市區內複雜之通勤路網,以作為政府相關單位日後考慮實施市區道路擁擠收費之藍圖。|
Abstract:The problem of traffic jam during the morning rush hour in Taiwan metropolitans is going from bad to worse day by day. Although the Government has making every effort to cope with the problem, there is little improvement in congestion reduction especially to city commuting routes. Road pricing policies for city commuting routes are considered in this project to reduce commuters' queuing times by decentralizing their departure times and altering their route choices. Because there are many substitute routes in city networks, commuters' choices of utilizing tolled or free routes to their destinations certainly affect effects of road congestion pricing on queuing reduction. Therefore, commuter behaviors under road pricing are important references for the authorities if congestion tolls levied on city streets are considered. Since commuting queuing frequently happened at road bottlenecks, this project is going to choose a congested bottleneck in city networks as the tolled route. Because the tolled and free routes in city networks often substitute and compensate mutually, how to effectively forecast commuters' route choice behaviors and equilibrium departure decentralization outcomes under congestion tolls are important works before pricing the city streets. Variables involved for this forecast are various and complex, it is difficult to develop a formula that can be suitable for all possible circumstances. Because of this difficulty, this project will adopt the method of traffic assignment used in the aggregate sequential demand model to forecast commuters' route choices and departure decentralization behaviors under the road congestion pricing on city streets. The step tolls developed by Laih will be applied to be the road pricing scheme in this project. Since the background of Laih's model is the unique bottleneck existed in the unique commuting route, commuters have no alternative choices but altering their departure times under step tolls. This project extends the pure assumption of Laih's model to a road network in the downtown. Then this project derives the behaviors of commuter' route choices and departure decentralization under the optimal step toll scheme. The purpose of developing the model of pricing a road network is going to achieve the equal rate of traffic flow to the capacity of each link in the network by levying the optimal step toll. Therefore, the existing condition of unbalanced traffic flow in the commuting network can be improved. This project will make the optimal step toll scheme to be more suitable for complex commuting networks. Consequently, it is expected that this project can be a blue print of road pricing on city streets for the authorities.