中文摘要：

从实测得到的210920中国城市快速路＂车速--车头间距＂数据中,选取包含26773条数据的3个样本作为不同类型交通流的代表,对多个交通流＂速--密关系＂模型进行参数优化和拟合优度比较研究,给出优化模型参数的定性和定量规律.修正形式的Kerner-Konhauser平衡函数和Payne平衡函数通过参数优化,分别在畅通和拥挤条件下具有优度相对最高的拟合结果,Greenshields模型（等价地,m=3时的一维管流模型）则对介于两种条件之间的实测数据具有优度相对最高的拟合结果.

英文摘要：

Traffic flow models are important means to describe various complex traffic procedures and to establish intelligence traffic systems of urban freeway. Generally the formation of a traffic flow model requires massive observation as well as in-depth analysis of real road traffic. Empirical data are indispensable to identify the parameters of the corresponding model. It is drawn in this paper that 210 920 ＂car velocity-headway distance＂ data pairs are obtained from the long time video recordings of urban freeway in four Chinese cities. Three traffic flow data-samples are made up of parts of these measuring data and are applied to an optimization study of several manifold well-known traffic flow velocity-density models. Some qualitative and quantitative results of the optimal free velocity value in the models have been obtained. The superiorities of modified Kerner-Konhauser equilibrium function and Payne＇s one are found in simulating the measuring data under the traffic condition of be free and be crowd, respectively, while Greenshields model （i.e. 1D pipe fluid model when m = 3） can give the satisfying results for the measuring data when the traffic condition is between free and crowd.