Abstract: Traffic volume forecast is essential to plan ,design ,invest ,build and manage expressways ,and provides quantitative basis for the management of expressways .By considering the different functions and characteristics between traditional expressways and expressways in metropolitan stretches ,the idea of urban transportation modeling is adopted to forecast expressway traffic volume .Moreover ,a new method ,Slip Predicting and Dynamical Verification ,is put for-ward .By modeling elaborately in large region ,the way of dynamical verification with multiple indexes and multiple years is used based on the network-charging-data ,which leads to the high accuracy of expressways traffic volume forecast .Be-sides ,a friendly user interface of transport model system is designed ,which can improve the model system's practicality .