In order to describe the stochastic road network with time-varying congestion degree, a novel variable cell transmission model is proposed. The model is based on each lane of the road network. Each lane is divided into lane cell and intersection cell. The two cells of same lane, one falling and the other one rising, interact. Lane cell model and intersection cell model are established respectively. The average speed of lane cell and congestion degree of the intersection cell are used as the model output. Co...