In traffic forecasting, which geographic unit is used to divide a region into similar land-use areas for modeling?

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In traffic forecasting, you divide a region into units that reflect similar land-use patterns so the model can estimate where trips are produced and attracted. The standard geographic unit for this purpose is Traffic Analysis Zones (TAZs). TAZs are designed to be small enough to capture differences in land use and trip generation, yet large enough to provide reliable data. They are typically built by aggregating smaller blocks and linking to socio-economic attributes and the transportation network, which allows the model to perform trip generation, distribution, mode choice, and assignment in a coherent way. Census tracts, ZIP codes, and school districts are administrative or service boundaries not tailored to travel behavior or the data needs of a regional model, so they’re not used as the primary unit for traffic forecasting.