  The transport approach is a useful tool to study dynamics of non-equilibrium
systems. For heavy-ion collisions at intermediate energies, where both the
smooth nucleon potential and the hard-core nucleon-nucleon collision are
important, the dynamics are properly described by two families of transport
models, i.e., the Boltzmann-Uehling-Uhlenbeck approach and the quantum
molecular dynamics approach. These transport models have been extensively used
to extract valuable information of the nuclear equation of state, the nuclear
symmetry energy, and microscopic nuclear interactions from intermediate-energy
heavy-ion collision experiments. On the other hand, there do exist deviations
on the predications and conclusions from different transport models. Efforts on
the transport code evaluation project are devoted in order to understand the
model dependence of transport simulations and well control the main
ingredients, such as the initialization, the mean-field potential, the
nucleon-nucleon collision, etc. A new era of accurately extracting nuclear
interactions from transport model studies is foreseen.
