COMPUTATIONAL ISSUES

Computational issues are discussed in detail in two separate papers (11,16). The two main results from those investigations are:

Using a Pentium cluster with 64 CPUs and Myrinet communication, the queue simulation on the 6-9 scenario runs nearly 200 times faster than real time. Although demand stops coming in at 9am, traffic is simulated until noon, which results in about 4 min of computing time for the queue simulation.

The feedback algorithm, including re-routing and agent database operations, takes roughly 45 min. This is clearly the bottleneck of the current approach; better implementations are under investigation.

In summary, an iteration using our current implementation takes less than one hour. Running fifty iterations thus takes about two days.