高速公路出口匝道區段之容量與服務水準分析方法

Development of Capacity and Level of Service Analysis Method for Freeway Off-Ramp Area

高速公路出口匝道區段為高速公路系統容易產生瓶頸的地點之一，但國內有關此一區段之容量與服務水準分析之研究文獻極為少見。本研究之基本目的即在依據國內實際調查資料與分析結果，針對我國之環境、交通與駕駛人行為特性，發展一套適用於國內高速公路出口匝道區段之容量與服務水準分析方法。本研究主要內容包括(1)車流運行特性調查與分析(2)服務水準最差地點與主線受影響範圍分析(3)相關車流模式之構建與檢測(4)容量推估與服務水準等級之界定，以及(5)服務水準評估方法之研擬等。本研究所構建的相關模式，包括車道流量分佈模式、流量－－速率－－密度模式，以及密度與速率推估模式經檢驗結果均具有相當不錯的解釋能力與合理性。所研議的服務水準分析方法可以應用於國內現有設施服務水準之分析與改善措施預期績效之評估，方可應用於新設施之規劃設計。

In our country, very limited effort has been devoted to study capacityand LOS of freeway off-ramp area, which can easily become bottleneck of thesystem. The basic purpose of this study is aimed to develop a set of procedurefor analyzing capacity and level of service of freeway off-ramp area based onlocal data, which is expected to be suitable for our local conditions. The majoritems of this study include (1 ) data collection and analysis of trafficoperational characteristics. (2 ) Identification of bottleneck location andanalysis of influenced area of freeway main lines. (3 ) Models development andtesting (4 ) capacity estimation and classification of level of service, as wellas (5) development of LOS analysis procedure. It reveals that all modelsdeveloped in this study are fairly reasonable, and fit local data very well,including lane volume distribution models, traffic flow models, as well asdensity and speed prediction models. The LOS analysis method proposed in thisstudy can be used to evaluate the service quality ofexisting facilities, and topredict the effect of improvement measure. It can also be used in planning anddesign of new facilities.