APPLICATION OF SPATIAL STRATIFICATION FOR SURVEY SAMPLE DESIGN

Transcription

1 APPLICATION OF SPATIAL STRATIFICATION FOR SURVEY SAMPLE DESIGN Petya Maneva, Maricopa Association of Governments Presenter

2 PROJECT TEAM Maricopa Association of Governments: Vladimir Livshits Petya Maneva Edward Brown Cambridge Systematics: Arun Kuppam Brent Selby 2

3 APPLICATION OF GIS IN SURVEYS SUMMARY Spatial stratification for households and establishments surveys Oversampling for hard to reach populations in the household survey Production plan for the establishment survey On going quality control of the collected data from both surveys Visualization of intermediate and final files from the surveys 3

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5 Survey Design GPS Data Collection Recruitment Smartphone App GPS Logger Backend Server Processing GPS Travel Points Travel Speed Travel Direction Longitude, Latitude Time/Date Participants Validate Travel Diary Completed Records 5

6 STRATIFICATION CRITERIA FOR SAMPLING THE HOUSEHOLD SURVEY 1. Household Income 2. Household Size 3. Hard to Reach Status o Hispanic Community Households o Large Households o Low Income Households o Young Professionals o Zero Vehicle Households 6

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8 SHARES OF HARD TO REACH POPULATION GROUPS Variable Share of Total Universe Source Zero car households 6.64 % Households ACS Transit Trips 1.20 % Total Average Daily Trips MAG 2015 Model Hispanic population Young professionals (25 39) % Population ACS 5.93 % Population ACS 8

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10 FINAL RATES WITH OVERSAMPLING Area/Workers Sampling Rate 0 Worker 1 Worker 2+ Workers Total Transit Intense 0.92% ,000 0/Auto Deficient 0.42% ,098 Hispanic 0.42% ,822 Rest 0.42% ,080 Total 0.45% 1,865 2,891 2,243 7, % 0.46% 0.45% Sampling Rate 10

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12 MAG ESTABLISHMENT SURVEY 2016 SAMPLING PLAN 12

13 STRATIFICATION CRITERIA FOR THE ESTABLISHMENT SAMPLING Visitors and Employees Survey Sample of 2,000 Establishments Commercial Vehicles Survey Sample of 400 Establishments o Industry Sector o Industry Sector o Company size o Square Footage of Facility o Job Density 13

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15 SAMPLE STRATIFICATION FOR 136,122 ESTABLISHMENTS Area Type Central Middle Periphery Central Middle Periphery Number of Employees Commerce ,961 3,984 2,169 4,515 1, Education & Pers. Serv. 11,569 24,740 9,913 3,161 5,303 2, Heavy Industries 4,542 9,499 4,999 2,026 2, Professional services 6,622 11,344 4,630 1,610 1, ,712 55,544 23,526 8,966 13,898 Total 4,979 5,009 1,467 15

16 QUOTAS FOR EACH STRATUM FOR A TOTAL OF 2,000 SAMPLE Area Type Central Middle Periphery Central Middle Periphery Number of Employees Commerce Education & Pers. Serv. Heavy Industries Professional services Total 16

17 QUOTAS FOR EACH STRATUM OF THE COMMERCIAL VEHICLE SURVEY Samples Sizes by Bins with no Oversampling Sector Sector Names Code 1 Agriculture/Mining/Utility Construction Manufacturing Retail trade Services includes Wholesale and Transportation/Warehousing Office Size Under 20,000 Over 20,000 Total sqf sqf Total 17

18 USE OF GIS FOR THE PRODUCTION SCHEDULE OF THE ESTABLISHMENTS' SURVEY Must Have High priority criteria: o Equal number of establishments o Compliance with the boundaries of the employment centers o Minimal the travel time of staff to the companies sites Nice to Have Criteria: o Compliance with area types definitions from the spatial stratification aspect of the sampling plan o Consideration for the topographic characteristic of the area o Accessibility from freeways and arterial streets 18

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20 QUESTIONS Contact Information: Vladimir Livshits : vlivshits@azmag.gov Petya Maneva : pmaneva@azmag.gov 20