工作時間制度與道路擁擠費對單一瓶頸路段通勤者旅次延滯之影響

Abstract

採行彈性、錯開工作時間制度與徵收道路擁擠費，以分散尖峰交通需求達到減輕交通擁擠之效果是運輸需求管理(TDM)所強調的重要管理策略。本研究利用使用者均衡原理構建數學分析模式，探討單一瓶頸路段於不同工作時間制度(包括固定、彈性與錯開工作時間制度)及不同道路擁擠費收費方式(包括不收費、最佳與次佳階梯式收費)等分散尖峰擁擠策略對系統等候延滯等績效值之影響，並以簡例及敏感度分析進行測試。 由研究結果顯示，在工作時間制度策略方面，相較於固定工作時制，彈性工作時制對於等候延滯之減少為彈性時間長度與瓶頸路段擁擠時間長度之比例平方(e/S)2呈正比；均勻式錯開工作時制對於等候延滯之減少為錯開時間長度與擁擠時間長度之比例(d/S)呈正比。無論採彈性或均勻錯開工作時制，最大等候長度之減少均為彈性（錯開）時間長度與瓶頸路段擁擠時間長度之比例(e/S, (d/S))呈正比。至於分段式錯開工作時制，在人數控制得宜情況下(即分段人數安排為相互之錯開工作時間乘以瓶頸路段設施容量)，更可獲致較彈性或均勻式錯開工作時制更佳之效果。 在徵收擁擠費策略方面，於彈性工作時制下採階梯式擁擠費對系統等候延滯之減少，較固定工作時制更有效果。在均勻錯開工作時制下，其最適階梯式費率均較固定工作時制小。採最佳階梯式擁擠費會發生部分通勤者因不願繳擁擠費，而於收費站前暫時等待，直到費率降低時才通過之現象。本文另提出次佳階梯式擁擠費，將可完全消除此一等待現象，惟系統績效值較最佳階梯式略差。

Flexible working schedules, staggered working hours and congestion tolls are highly emphasized tactics in transportation demand management (TDM) which are used to reshape peak traffic demand to reduce congestions. This study attempts to employ user equilibrium principle and queueing theory to formulate analytic models at a single bottleneck to evaluate and compare peak traffic delays resulted from such alternative work schedules and congestion tolls. Numerical examples and sensitivity analysis are performed. In the subjects of working schedules, the results show that, traffic delays reduced by flexible working hours, compared with conventional fixed working hours, are in squared proportion to the flextime length - peak duration ratio (e/S)2. By contrast, the reduced traffic delay incurred by staggered working hours of uniform-type is linearly proportional to the ratio of staggered time length to peak hour period, (d/S). The maximum queue length reduced by flexible/staggered working schedules is also linearly proportional to the ratio of flexible or staggered time length to peak hour period, (e/S or d/S). Moreover, the staggered working hours of step-type can yield even better performance if the steps are optimized in such a manner that the staggered time multiplied by the bottleneck saturation flow rate controls the number of commuters in each step. In the subject of congestion tolls, the results show that, the benefit brought by optimal step-tolls under flexible working hours is more than the ceiling of fixed working hours. The optimal step-toll fees under staggered working hours should be lower than those under fixed working hours. At optimal step-tolls, it appears that some commuters would be reluctant to pass through the toll station at the transitions from higher step-tolls to lower ones. Introducing suboptimal step-tolls will completely remove such “reluctant queues,” however the systems performance is slightly less effective than the optimal step-tolls.