Abstract: The paper rewrites the traffic flow macro models in the form of system of quasilinear hyperbolic partial differential equation of first order，and classifies the models in terms of the coefficient in the equation. According to whether the characteristic speed is smaller than macroscopic speed and whether the model depends on foreign speed- density equilibrium relation，and according to the flow characteristic shown in the model，the paper proceeds to evaluate some models. Finally, the result shows that three ideal models of the traffic flow are fit for studies.

Key words: traffic flow theory, partial differential equation, macro model, characteristic method

摘要： 将交通流模型表示成拟线性一阶双曲型偏微分方程组;按照方程组中的系数值，对交通流的各种宏观模型进行了分类;依据特征线的特征速度是否小于宏观运动速度，模型是否依赖外来的速度一密度平衡关系以及模型代表的交通流特点等三项指标对模型进行了评价.结果表明有三种比较理想的交通流模型.

关键词: 交通流理论, 偏微分方程组, 宏观模型, 特征线法