  Co-evolutionary processes are according to the evolutionary urban theory at
the center of urban systems dynamics. Their empirical observation or within
models of simulation remains however relatively rare. This chapter is focused
on the co-evolution of transportation networks and cities and applies high
performance computing numerical experiments to the SimpopNet co-evolution model
in order to understand its behavior. We introduce specific indicators to
quantify trajectories of such models for systems of cities, and apply these to
exhibit co-evolutionary regimes of the model. This illustrates how the
systematic exploration of a simulation model can qualitatively transform the
knowledge it provides.
