b'Forecasting Tools in a Time of Uncertainty and DisruptionPractitioners can undertake scenario planning usingINTEGRATED MODELS AND NETWORK-BASED myriad methods and tools. While this white paperTRAVEL DEMAND MODELSprovides an overview of several tools, its focus isIntegrated models include a network-based travel on strategic models, which offer advantages whendemand model onto which they assign trips by origin, compared to other tools: destination, mode, and time of day. These types ofIntegrated models and network-based travelmodels are more sophisticated and can produce demand models incorporate multiple travel,detailed performance metrics. Longer run times and economic, land-use, and other models to representmore complexity make them better suited to exploring their diverse, dynamic, and interrelated aspects. a smaller decision space and evaluating fewerSketch planning tools are used to produce roughvariations (e.g., land-use changes, modal availability, order-of-magnitude travel demand estimates forcongestion pricing). These models require expertise different scenarios. and detailed data to develop and maintain. Strategic models are travel demand models that One of the biggest barriers to using an integrated use a disaggregate demand representationmodel for modeling future scenarios is that coding with an aggregate representation of themultimodal networks, especially for future years, is a transportation network supply. These models canlabor-intensive and time-consuming process. The large help practitioners quickly analyze hundreds ornumber of model parameters and the connections thousands of scenarios. between the models requires more effort and time, By running these tools with a range of inputwhich may not be warranted by the analysis.assumptions, practitioners can evaluate the differencesThe design of integrated models relative to other between alternatives using a broad range of metrics.scenario planning tools makes them less nimble. Table 1 compares various tools across several criteria. This downside is apparent when forecasting the Strategic models include more complex behavioralaggregate impacts of emerging technologies or when representations than sketch planning tools but lessexploring scenarios farther into the future where more network characteristic specificity than travel demanduncertainty exists. With the political and technological models. They balance rapid computation with accuratelandscape around ACES mobility evolving so quickly, representation. By using a high-level zonal geographyand the travel impact of COVID-19, modeling many rather than a network, these tools can quickly evaluatescenarios with network-based travel demand models multiple alternative scenarios. would be cost prohibitive and time consuming.TABLE 1.COMPARISON OF TOOLSSPATIAL/ PERSON/ POLICYTOOL TYPE TEMPORAL HOUSEHOLDSENSITIVITYRUN TIME COSTDETAIL DETAILIntegrated Model low-moderate moderate moderate moderate moderate-high(trip-based)Integrated Modelmoderate-high high moderate-high moderate moderate-high(activity-based)Sketch Planning low low low low lowStrategic Model low-moderate moderate-high moderate-high low lowSource: RSG, 202022020 RSG'