Parallel Traffic Flow Simulation of Freeway Networks: Phase 2

摘要

Explicit and implicit numerical methods for solving simple macroscopic trafficflow continuum models have been studied and efficiently implemented in traffic simulation codes in the past. The authors have already studied and implemented explicit methods for solving the high-order flow conservation traffic model. Implicit methods allow much larger time step size than explicit methods, for the same accuracy. However, at each time step a nonlinear system must be solved. The authors use the Newton method coupled with a linear iterative (Orthomin). The authors accelerate the convergence of Orthomin with parallel incomplete LU factorization preconditionings. The authors implemented this implicit method on a 16 processor nCUBE2 parallel computer and obtained significant execution time speedup.