號誌化平面交叉路口序別直行車微觀紓解模式之研究

Abstract

號誌化交叉路口向為都市地區道路系統之主要交通瓶頸，是車輛衝突與延滯最常發生的地點，因此如何有效針對路口交通特性加以分析，並適時提供一具有安全、效率及順暢的控制措施或策略，是研究號誌化路口的重要課題。又由於交叉路口的車輛紓解特性對交叉路口的容量評估影響甚鉅，而紓解率的應用常換算成飽和流率，進而推算出理論容量值。因此，車輛紓解特性因素，在整個道路口容量與分析中佔了相當重要角色。 過去多數交叉路口車輛紓解行為之研究，多探討穩定車流下純小客車之紓解率，或以小客車當量數轉換大車的紓解情形，較少以微觀的方式來探討車流紓解趨於穩定前後之序別車輛的不同車種紓解特性，此乃一值得研究之課題，而本研究中「序別」係指當號誌為紅燈期間，依停止線由前往後之個別停等車輛所排序之相對停等位置的順序關係。故本研究針對較單純的號誌化交叉路口之直行車流進行調查，分析號誌化路口車流在紓解未達穩定與趨於穩定後之紓解特性，並將每車隊中前後兩輛車之車種分類成大車-大車、大車-小車、小車-大車以及小車-小車等四組樣本，探討前後兩車不同車種組合間紓解間距之差異性，再以微觀角度構建序別車輛微觀紓解模式。此外，經由觀察發現在號誌紅燈轉換綠燈前，車輛會有搶先起動之行為，本研究亦將考量此行為特性進行探討。而本研究所得之結果，將可提供交通號誌時制設計與道路容量估計等相關研究之基礎。

Signalized intersections are always the main traffic bottlenecks of road system in urban areas, and it is the most frequently place to cause delay and conflict of the vehicles. Therefore, how to analyze the traffic characteristics effectively and provide safe, efficient and fluency strategy in time are very important issues for signalized intersections. Because discharging characteristics of the vehicles at intersections impact seriously on estimating capacity, discharge rates are often applied to change into saturated flow rates estimating theoretical capacity. Therefore, it played a quite important role in all road capacity analyses. Many studies of the queuing discharging behavior at the intersection, usually discussed the stable discharging rate of the passenger cars, or analyzed discharging characteristics of the heavy vehicles by transferring the passenger-car-equivalent. Few studies discussed in the microscope method and analyzed the vehicles types discharging characteristics of ordered vehicle before they are unstably and stably discharged. It is worth for study. Ordered vehicles mean the relative ordered position of queuing vehicles stopping in front of the stop line during red light. So this study aims at the characteristics of the straight traffic flow under simple signalized intersection, and analyzes the discharging characteristics of unstable and stable discharging traffic flow at the signalized intersection. According to forward-backward two types of vehicles, we classify four sets of vehicles samples as heavy-heavy, heavy-small, small-heavy, and small-small, and discuss the difference of the combination of two types of vehicles. Then we construct the Microscopic Discharging Model of Ordered Straight Vehicles. Besides, we find some characteristics that some vehicles start at the intersection before the green light phase begins. We will discuss the characteristics of this behavior. The results of this study could be referenced for the base for estimating the capacity of lanes, designing signal, the relevant research and etc.