A study of micro-simulation uncertainty of space development module of Baltimore PECAS Demo Model

Precise and stable micro-simulation of space development is fundamental for supporting various related policy analysis and decision-making through integrated land use and transportation models (ILUTMs). The purpose of this paper is to study the dynamics or uncertainty of micro-simulation outputs from the space development module of an ILUTM - Baltimore PECAS Demo Model. The simplified Demo model is tested under the following two scenarios: (1) Run the full PECAS model three times over the entire planning window from Year 2000 to 2030; and (2) Run the model 30 times just one year ahead from 2000 to 2001. Then the outputs obtained from the two scenarios are then used to analyze such dynamics or uncertainty. Study results from the first scenario show that, in general, the simulation results are very much similar to each other, and the system is fairly stable and consistent over runs and time, as supported by a set of paired t-tests. On the other hand, the coefficient of variation (COV) measuring the variation of estimated space quantity (by category) over four cross-section years do indicate that the differences among runs are increasing over time through planning window. The COV test over the second scenario indicates that the estimated space quantity is stable for most of zones, except for a small portion of zones with a small space quantity, due to their inertia effect. In general, the results suggest that the PECAS Space Development module show a high reliability in micro-simulating space development.