Firstly, we calculated several statistics relating to the population forecast. Secondly, ba-sed on the Logistic prediction models, against Logistic model defects, we obtained the improved prediction model. Finally, using China's total population in 2004 as the initial population, we predict the total population of China in the next 30 years and in 2050 year by applying the model.

Based on two traffic accident data, during the accident occur and evacuation, we analyze the changing process of the actual traffic capacity on cross-section where the accident happened. We can get the vehicle actual traffic capacity in Accident 2 is larger than the vehicle actual traffic capacity in Accident 1. And build a mathematical vehicle queue length model.