We presented a framework for dynamic traffic assignment. The fast implementation of the traffic-simulation and the use of parallel computers allows us to compute a self-consistent route-set for the morning traffic (4 a.m. to noon) within two days of computing on a 8 CPU (250 MHz) machine for a problem with about 6000 links. Moving to a realistic representation of a medium-sized complete city such as Portland/Oregon (1.5 mio people) and to simulations of whole days (24 hours), one would need a 250 CPU machine to obtain the same result after a similar computing time. This predictive result is based on: (i) development of equations for computational speeds from systematic tests with the 6000 links problem; (ii) assumptions about the characteristics of the target computer; and (iii) knowledge about the efficiency of our geometric domain decomposition for the street network of Portland. Preliminary runs confirm the predictions.