Composite Travel Generative Adversarial Networks for Tabular and Sequential Population Synthesis
This addresses the need for disaggregate travel demand data in transportation modeling, offering a novel method for population synthesis, though it is incremental as it builds on existing generative models like GANs and VAEs.
The paper tackles the problem of synthesizing population data for agent-based transportation modeling by introducing a Composite Travel Generative Adversarial Network (CTGAN) that generates synthetic agents with both tabular and sequential mobility data. The results demonstrate consistent and accurate generation of synthetic populations across varying spatial scales and dimensions.
Agent-based transportation modelling has become the standard to simulate travel behaviour, mobility choices and activity preferences using disaggregate travel demand data for entire populations, data that are not typically readily available. Various methods have been proposed to synthesize population data for this purpose. We present a Composite Travel Generative Adversarial Network (CTGAN), a novel deep generative model to estimate the underlying joint distribution of a population, that is capable of reconstructing composite synthetic agents having tabular (e.g. age and sex) as well as sequential mobility data (e.g. trip trajectory and sequence). The CTGAN model is compared with other recently proposed methods such as the Variational Autoencoders (VAE) method, which has shown success in high dimensional tabular population synthesis. We evaluate the performance of the synthesized outputs based on distribution similarity, multi-variate correlations and spatio-temporal metrics. The results show the consistent and accurate generation of synthetic populations and their tabular and spatially sequential attributes, generated over varying spatial scales and dimensions.