構建高速公路出口匝道車流回堵對主線車流影響模式

Abstract

部分都會區交流道與重要平面幹道相接，這些交流道於上下午尖峰時間時容 易發生重現性壅塞現象，其中一種壅塞現象為出口匝道停等車隊回堵。此一現象 的成因為，當出口匝道與平面幹道需求量同時增加的時候，出口匝道鄰接的平面 路口若無法即時紓解等候車隊，將使出口匝道等候車隊逐漸變長，一旦出口匝道 等候車輛數超過減速車道儲車空間，將使出口匝道等候車隊回堵至上游主線並佔 據主線外側車道，影響主線直進車流的運行。本研究以國道一號 91 公里處竹北 交流道為例，研究分析當上述壅塞情況發生時，其外側車道等候車隊對於主線車 道直進車流所造成的影響。而本研究考量現實資料密度的不足，遂以模擬的方式 輸出所需資料。本研究先行調整校估模擬模式的參數，採用 GEH 指標檢定模擬 所產生之資料與實際資料的吻合度，確認模擬產生的資料與現實資料相吻合後再 以該模擬模式輸出本研究所需資料。本研究以圖表的方式分析不同等候車隊長度 對於主線直進車流的影響程度及範圍，並據其建立一個數學模式以計算主線車輛 的延滯時間。

Recurrent congestions would occur at some interchanges which intersect with busy arterials in urban at peak hours. One of such congestions is off ramp queues spillback onto freeway main-lane. The cause of this phenomenon is, if off ramp queues could not be discharged instantly when the demand for off ramp and arterial increase at the same time, the off ramp queues would become longer. While the storage of deceleration lanes is not sufficient for the off ramp queues, these queues would spillback onto freeway main-lane and occupy the most outside lane. Such phenomenon would slow down the speed of through traffic and decrease total throughputs on main-lane. This research uses Chupei Interchange located on 91 km of Freeway No.1 as case to analyze the effect on main-lane traffic when the fore mentioned congestion occurs. Due to the insufficient real data for our research, a simulation method would be applied in this research. We would first calibrate the parameters in simulation model, then using GEH as an index to test if simulation outputs coincide with real data. After the test results are accepted, the simulation model becomes usable. The simulation outputs would be plotted into many charts to analyze the effect on main-lane traffic under different lengths of off ramp queues. An model is also constructed to compute the delay time of main-lane traffic.