On the Computation of Skims for Large Scale Implementations of Integrated Activity-based and Dynamic Traffic Assignment Models

1 Integrated activity-based modeling (ABM) and dynamic traffic assignment (DTA) frameworks have 2 emerged as a promising tool to support transportation planning and operations, particularly in the context 3 of novel technologies and data sources. This research proposes an approach to characterize 4 implementations of integrated ABM-DTA models, seeking to facilitate the interpretation and comparison 5 of frameworks, and ultimately the selection of appropriate tools. The importance of the dimensions 6 considered in this characterization is illustrated through a detailed analysis of one such aspect the 7 computation of skims. Skims are the level-of-service (LOS) metric produced by DTA models, and their 8 computation may impact the performance and convergence of ABM-DTA applications. Numerical results 9 from experiments on a regional ABM-DTA model in Austin, Texas suggest that skims produced at 10 relatively small time steps (10-30 minutes) may lead to a faster integrated model convergence. Finer time 11 grained skims are also observed to capture sharper temporal peaking patterns of the LOS. This work 12 considers two skim computation methodologies; results analysis suggests that simpler techniques are 13 adequate, as the inherent variability of travel times from simulation overshadows any gain in precision 14 from more complex methods. This study also uses promising techniques to visualize and analyze model 15 results, a challenging task in the context of highly dissagregate models that will be the subject of further 16 research. The insights from this research effort can inform both, future research on the implementation of 17 ABM-DTA methodologies and practical applications of existing frameworks. 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51