高速公路匝道流量控制模式之研究

Ramp Traffic Control Model on Freeway

高速公路係採完全出入管制，其車流行進具連續性、無阻斷性，可視為一流管系統，主線上之車波傳遞近似於可壓縮流體之波動理論，而此一系統特性將有助於應用流體運動理論來建立之高速公路車流波動模式。本研究將高速公路主線區分為基本路段與匝道影響區段，利用節點連續關係、車流理論之巨觀車流模式，及由Lighthill、Whitham與Richards所提出之流量守恆模式來描述高速公路上各路段之車流現象，並建立一階波動模式與高階波動模式，藉由一階波動模式的解析解法代入初始條件及邊界條件，建構高速公路之匝道流量控制模式。最後依據匝道流量控制模式，討論匝道進出流量與高速公路主線車流行為之互動關係，以提供高速公路研擬交通控制策略之參考。 Freeway system are characterized as being continuous, uninterrupted, and with all exits and entrances being regulated entirely. So we can treat the freeway system as a pipe system. The traffic flow on the mainline of freeway is propagated in a manner similar to waves in the theory on compressible fluid. And the above-mentioned characteristics are helpful to applying fluid dynamics in the freeway traffic wave models. In this study, freeway is divided into fundamental sections and ramp traffic impact area. We can describe the phenomenon of freeway traffic flow with node continuity, macroscopic traffic stream models and conservation of vehicles equation developed by Lighthill, Whitham and Richards. Then we can obtain first-order wave model and high-order wave model. After that, we establish the ramp traffic control model by using the analytic method in first-order wave model with initial condition and boundary condition. Base on the ramp traffic control model, we discuss the interaction between ramp traffic and mainline traffic flow to provide the reference of ramp control strategies.

Freeway system are characterized as being continuous, uninterrupted, and with all exits and entrances being regulated entirely. So we can treat the freeway system as a pipe system. The traffic flow on the mainline of freeway is propagated in a manner similar to waves in the theory on compressible fluid. And the above-mentioned characteristics are helpful to applying fluid dynamics in the freeway traffic wave models. In this study, freeway is divided into fundamental sections and ramp traffic impact area. We can describe the phenomenon of freeway traffic flow with node continuity, macroscopic traffic stream models and conservation of vehicles equation developed by Lighthill, Whitham and Richards. Then we can obtain first-order wave model and high-order wave model. After that, we establish the ramp traffic control model by using the analytic method in first-order wave model with initial condition and boundary condition. Base on the ramp traffic control model, we discuss the interaction between ramp traffic and mainline traffic flow to provide the reference of ramp control strategies.