  We describe a software framework for solving user equilibrium traffic
assignment problems. The design is based on the formulation of the problem as a
variational inequality. The software implements these as well as several
numerical methods for find equilirbria. We compare the solutions obtained under
several models: static, Merchant-Nemhauser, `CTM with instantaneous travel
time', and `CTM with actual travel time'. Some important differences are
demonstrated.
