The National Household Travel Survey NHTS AddOn Update

The National Household Travel Survey (NHTS) Add-On Update Huiwei Shen, FDOT Systems Planning

Florida’s Participation in the NHTS Add-On Program n n n Florida Model Task Force recommended participation in the National Household Travel Survey (NHTS) Add-On program MPOAC agreed to use 2. 6 million PL fund for 12, 000 samples at $175 per sample plus $500 K for data analysis FDOT funded $350 K for rural samples across the state

Sampling Plan Design n n n Developed in consultation with FHWA NHTS team Reviewed and approved by MTF Data Committee Conforms to existing FDOT boundaries Meets urban and regional modeling needs Original plan based on 2000 Census Households Revised plan guarantees that minimum sample size per region is 1, 200 Allows for meaningful comparisons

Sampling Plan n Region 1 – Collier, Lee, Charlotte, Sarasota, and Manatee (Census 2000 Households : 545, 158 ) Region 2 – Duval, St. Johns, Clay, Nassau, and Alachua (Census 2000 Households : 613, 890 ) Region 3 – Leon, Gadsen, Wakulla, Walton, Okaloosa, Santa Rosa, Escambia, and Bay (Census 2000 Households : 424, 149 )

Sampling Plan n n Region 4 – Broward, Miami-Dade, Palm Beach, Indian River, St. Lucie, and Martin (Census 2000 Households : 2, 150, 666 ) Region 5 – Orange, Osceola, Seminole, Lake, Sumter, Brevard, Volusia, and Marion (Census 2000 Households : 1, 040, 095 ) Region 7 – District 7 (except Citrus) and Polk (Census 2000 Households : 1, 196, 954 ) Region 8 – Rural counties not in the first six (Census 2000 Households : 370, 209 )

Sampling Plan Sample Size Number of Region Households Total Original Revised Confidence Interval (95% CI) Original Revised 1 545, 158 1, 096 1, 200 ± 3. 0% ± 2. 8% 2 613, 890 1, 234 ± 2. 8% 3 424, 149 852 1, 200 ± 3. 4% ± 2. 8% 4 2, 150, 666 4, 322 4, 116 ± 1. 5% 5 1, 040, 095 2, 090 2, 000 ± 2. 1% ± 2. 2% 7 1, 196, 954 2, 406 2, 250 ± 2. 0% ± 2. 1% 8 370, 209 2, 000 ± 2. 2% 6, 341, 121 14, 000 ± 0. 8%

Sampling Plan Region 1 Sample Size 1, 200 Region 2 1, 224 Region 3 1, 200 Region 4 4, 116 Region 5 Region 7 Region 8 2, 000 2, 250 2, 000

Sampling Plan n MPO Sample Size Each MPO will be sampled such that at least 80% of the sampled households from the MPO are included in the region sample Why do this? n n Ensures smaller MPOs are sufficiently sampled Makes data collection more cost effective

Rural Samples FDOT District Total Households Sample Size Confidence Interval (95% CL) 1 83, 828 453 ± 4. 6% 2 125, 436 678 ± 3. 8% 3 51, 894 280 ± 5. 9% 5 21, 284 115 ± 9. 2% 6 35, 106 190 ± 7. 1% 7 52, 661 284 ± 5. 8% 370, 209 2, 000 ± 2. 2% Rural Total

2001 NHTS Sample for Florida Region Sample Size Region 1 136 Region 2 158 Region 3 111 Region 4 401 Region 5 240 Region 7 295 Region 8 86

Additional Questions n General Questionnaire Improvements n n Elder Travel Transit Access Transportation Funding Preference Additional Questions for Florida n n n Residential Location Decision Seasonal Residents Transit Preference to Supplement General Questionnaire

NHTS Status n n n Awarded contract to Westat Completed Florida sampling plan Finalized Florida questionnaire Still need $$$ for the national samples Pretest December/January 2008 and full data collection March 2008 Setup reporting system on internet