The paper focuses on the review of analysis methods for traffic flow on road networks on account of the importance of its applications in intelligent transportation systems.It affords a meaningful review on the large-scale analysis methods for traffic flow.The basic types of the traffic flow analysis methods were drawn from the three aspects of microscopic,mesoscopic and macroscopic views at first.Then,the concept of traffic congestion index and its computing method were presented in detail,and at the same time,the concept of traffic index clouds was proposed.Finally,the methods for analyzing macroscopic traffic flow based on traffic index clouds were discussed,and the development and applications of the traffic index clouds were also presented.