A traffic analysis zone or transportation analysis zone (TAZ) is the unit of geography most commonly used in conventional transportation planning models.
The spatial extent of zones typically varies in models, ranging from very large areas in the exurb to as small as city blocks or buildings in central business districts.
Typically these blocks are used in transportation models by providing socio-economic data.
This information helps to further the understanding of trips that are produced and attracted within the zone.
This is done typically to eliminate unneeded areas to limit the computational burden.