Introduction

In order to explore and evaluate future potential scenarios that involve new policies, infrastructure changes or even minor operational logic changes, simulation models are often the most reliable option. On the other hand, the complexity of all relevant interactions in a simulation model demands simplifications that often compromise the validity of the results. For example, in mesoscopic traffic simulation models, vehicle movement can be determined by representations such as speed-density relationship functions, with parameters calibrated a priori. While this provides reliable results under habitual circumstances, under new scenarios such as incidents or infrastructure changes, the demand or supply model assumptions might have changed. The use of decoupled models to solve this (e.g. using a microscopic model to obtain new parameters where/when needed) can be a challenging solution since it demands full consistency between models (e.g. mesoscopic and microscopic) and is often difficult to implement in practice. From this perspective, a fully integrated simulation model, that considers macro, meso and microscopic levels, is an ongoing challenge with significant impact for future research and practice. There has been some progress in developing integrated frameowrks, however, most of the efforts have shown loosely coupled integration between demand (usually activity-based model(ABM)) and supply (dynamic traffic assignment(DTA)) models. SimTRAVEL (1) shown a step ahead by inserting landuse component within the integrated framework of ABM + DTA. Also, POLARIS (2) has claim to provide more flexible agent based platform to integrate separate models together but so far has been applied only to a level of integration that can be classified as ABM+DTA. Development towards fully integrated platform that integrates long-term, mid-term and short term model together is scarce, primarily due to its challenging nature.
This paper present a fully integrated agent based platform named as SimMoblity  which integrates various mobility-sensitive behavioural models within a multi-scale simulation platform that considers land-use, transportation and communication interactions. It focuses on impacts on transportation networks, intelligent transportation services and vehicular emissions, thereby enabling the simulation of a portfolio of technology, policy and investment options under alternative future scenarios. SimMobility incorporates three different sub-models:
This paper introduces the full SimMobility system, with focus on the innovative contributions that span across all levels. We emphasize the benefits and feasibility of a fully integrated approach, which relies, by design, on the acitvity-based modeling paradigm, with implications for all levels. The paper then disucsses the SimMobility through a case study with autonomous mobility which may have impacts on long-term, mid-term and short-tem levels, and is specifically designed to showcase advantages of integration across all thee levels .