Parallel implementation of the TRANSIMS micro-simulation

TL;DR

This paper presents a parallel implementation of the TRANSIMS traffic micro-simulation using domain decomposition, with methods for load balancing, information exchange, and performance prediction based on network partitioning and computer architecture.

Contribution

It introduces a systematic approach to parallelizing TRANSIMS with adaptive load balancing and performance prediction capabilities for different hardware configurations.

Findings

Parallelization improves simulation speed significantly.

Performance prediction enables feasibility assessment for studies.

Adaptive load balancing optimizes resource utilization.

Abstract

This paper describes the parallel implementation of the TRANSIMS traffic micro-simulation. The parallelization method is domain decomposition, which means that each CPU of the parallel computer is responsible for a different geographical area of the simulated region. We describe how information between domains is exchanged, and how the transportation network graph is partitioned. An adaptive scheme is used to optimize load balancing. We then demonstrate how computing speeds of our parallel micro-simulations can be systematically predicted once the scenario and the computer architecture are known. This makes it possible, for example, to decide if a certain study is feasible with a certain computing budget, and how to invest that budget. The main ingredients of the prediction are knowledge about the parallel implementation of the micro-simulation, knowledge about the characteristics of the partitioning of the transportation network graph, and knowledge about the interaction of these quantities with the computer system. In particular, we investigate the differences between switched and non-switched topologies, and the effects of 10 Mbit, 100 Mbit, and Gbit Ethernet. keywords: Traffic simulation, parallel computing, transportation planning, TRANSIMS