To see first hand how the TAZ/TAD development software works Why are we here Today?

Introduction to CTPP TAZs and TADs What is CTPP TAZs and TADs Things to think about Resources

What is the CTPP? Census Transportation Planning Products (CTPP) Program The CTPP is an umbrella program of Census related data products, custom tabulations, training, technical assistance, and research for the transportation community Designed and paid for by transportation planners for transportation planners

Why are Custom Tabulations so important? Summarize data by Place of Residence Place of Work Flows between Home and Work Unique Universes (e.g. workers in HHs) Custom Geography (Local TAZs) Traffic Analysis Zones - defined by the local transportation data user for the local transportation data user

Sometime in 2013 New Product is due out New Geography NO data will be suppressed XXXXXXXXX Sometime in 2013

What is a TAZ/TAD? ● Custom Geography for CTPP data tabulations ●Defined by MPOs and State DOTS ● Developed in Spring/ Summer 2011 ● Funded under CTPP Program ● GIS equivalency process built from Census Blocks TAZ Traffic Analysis Zone Traditional Size TAD Traffic Analysis District 20,000 population

What is an equivalency process? Take the map at the right and using the states boundaries make 9 contiguous regions It’s the same for TAZs Blocks cluster into TAZs

TAZs/TADs Building Blocks ● 2010 Census Blocks will make up TAZs ● TAZs will make up TADs ● TADs can cross Counties and States ● TADs can be built from TAZs, Block Groups or Tracts

Nov/Dec Agencies verified contact names Feb Web-based training (2-25 and 2-28) March through April Online delivery of software and Census 2010 data and geographic files (Rolling basis) 3- Months to delineate TAZ/TADs June through July Files returned to CB Geography TAZs/TADs Inserted into TIGER data base The Schedule 2010 TIGER files

TAZ Size CB recommends ~600 persons corresponds to the minimum threshold for 2010 Census Block Groups Threshold is guideline not a requirement TAZs may be defined with fewer than 600 residents or workers Data reliability and availability improves as population size increases Bigger is Better

Why the hang-up on TAZ size Big Zones make happy data ● ACS is a small sample ● Smaller areas have lager MOES ● Statistical Collapsing ● Confidentiality and Disclosure rules

Important concept to follow When is a TAZ Not a TAZ? When it is a C-TAZ

Important Concept TAZs and TADS for Census ACS data do not have to be the same as the TAZs used in your travel forecasting models Think of these as Census TAZs or (CTAZs) Census TADs or (CTADs) Travel Forecasting Zones as Planning Zones or Planning Units Large Zones are Better for ACS Data Hmmm TAZs  TAZs

Why are TADs so important? ● Higher quality data ● Less chance for disclosure proofing ● More real data ● Potential 3-year data coverage w/No Swiss Cheese NE Illinois ( year ACS)

5-year Geography and Flows ● Asymmetrical Flows ● Small Areas defined by MPOs in MPO areas and States Elsewhere ● Tracts are Defaults for Small Areas ● Default TADs under discussion TADs as CBDs, Special Districts, etc

16 The Software Using the Census Bureau MAF/TIGER Partnership Software Census Bureau Contract (CTPP Paying for it) Caliper is the contractor Calling it the MTPS TAZ Element formally TAZ-UP Download materials, software and files from Census Bureau site.

Some TAZs resource materials files/PPT_12_TAZ%20White%20Paper_NOV07_FINAL_CS_Keli_Wu.ppt FDOT_TAZ_White_Paper.pdf Florida Standard Urban Transportation Model Structure White Paper on Recommended Approach to Delineating TAZ

Important sizes / More on PSAP How many Block Groups can be contained in a single Tract?

Thank You Ed Christopher FHWA Resource Center 4749 Lincoln Mall Drive, Room 600 Matteson, IL