高速公路二車道瓶頸路段車流模擬之初步研究

A Preliminary Research on the Traffic Flow Simulation of Two-Lane Freeway Bottlenecks

本研究置在建構和模提高速公路瓶頸路段的車流模式，以描述高速公路瓶頸路段的車流特性。假設高速公路上一均質、無進出口區道的二車道路段，其中有一車道的部份路段封閉，觀察未封閉車道的車流特性，以流量守恆律為基礎，構建該瓶頸路段的車流模式，再以特徵曲線法求解模式得車波軌跡函數及密度函數，最後利用有限差分法模擬在不同初始密度狀況下的車流情形，並瞭解車軒在瓶頸路段回堵變化之動態過程，作為車流變化及預測研究之參考。

The pupose of this research is to simulate the characteristics of traffic flow at bottlenecks. In this study special case of a uniform two-lane freeway(with no entrances or exits), in which part of a lane is closed, is discussed. The mathematical models of traffic flow describing the dynamic evolution of traffic variables along the normal lane are developed by conservation law and the momentum equation. The models are solved by method of characteristics and simulated by finite difference method. The process of back-up at bottlenecks would be comprehended and that would be used in the forecast of traffic behavior.