This paper has three additional authors: Matthew Kitchen (PSRC), John Long (DKS), Maren Outwater (RSG)


The activity-based (AB) models at the Puget Sound Regional Council (PSRC) provide a unique opportunity to compare the features and performance of a household activity-based model with those of a person activity-based model. After implementing a person-based model system, the models were enhanced to incorporate coordinated household members’ activity patterns, joint tours and shared escort rides to work and school, while preserving the model system’s downward and upward integration features, implementing them on the same software platform, integrating them with the same auxiliary demand and network supply models, and using the same iterative demand-supply model equilibration procedure.

In this presentation and paper the two implementations of the AB model system are compared in the following ways:

The two AB model structures are compared, including an explanation of features that remain the same—such as the use of accessibility measures to preserve upward integration—as well as a description of the household models and the differences these introduce.

Fundamental features of the AB modeling system are described, focusing on how the same system accommodates a household model structure as well as a person model structure.

The iterative demand-supply model system and hardware set-up shared by both implementations are described.

The two model systems are compared in operation, including:

--model system run times, identifying the extent to which adding household models increases run time,

--simulated outcomes of one or two specific households, showing how the household models yield more realistic household schedules, and

--preliminary scenario sensitivity tests, identifying how the household model changes the AB model system’s sensitivity to policies.