Best Practices Met Council Household Travel Survey (HTS) 2010-2012 May 8. 2013.

Best Practices Met Council Household Travel Survey (HTS)2010-2012

May 8. 2013

Metropolitan Council Household Travel Survey: Design, Implementation, and Lessons Learned

14th TRB Planning Applications Conference 5-9 May 2013Columbus, OH

Authors:Jason Minser, Abt SRBILaurie Wargelin, Abt SRBIJonathan Ehrlich, Metropolitan CouncilAnurag Komanduri, Cambridge SystematicsKimon Proussaloglou, Cambridge Systematics

Cemal Ayvalik, Cambridge Systematics.

The HTS was Part of a Total Travel Behavior Inventory with Cambridge Systematics as Prime

Household Travel Survey (HTS) Overview

• 19-counties in Minnesota (16) and Wisconsin (3)

• Address-based sampling approach – three tiered stratification plan

• Comprehensive inventory of . . . 12,000 households’ 24-hour travel for persons 6 years

of age and older

Subsample of 250 GPS households

• Special subgroups MnPass users

University students

4

Why Address-Based Sampling (ABS)?• Includes cell-phone only households

• Supplemental cell phone data collection is expensive with low response rates – not geographically based

• With ABS geographically based sample can be pulled and weighted by census tract

• Duel frame sampling (ABS/RDD) is difficult to weight

Weighting is not the solution to unrepresentative samples – only builds in the bias.

5

ABS Allows Targeting by HH Type

• As random, proportional data collection proceeds to 60-75% of recruitments, results are monitored and examined on a weekly basis

• Since ABS is census tract/block based – at this point - oversamples can be ordered for tracts/blocks with high incidence rates for under-represented variables of interest—i.e. those with H2R household characteristics

• Examples (Zero-vehicle HHs, 4+ person HHS)

• Implementation can be targeted by geographic area

This approach is called Responsive Interviewing Design (Groves and Herringa )

Highly Stratified ABS Sampling Plan• ABS improves the ability to define geographic strata

7 distinct regions sampled at differential rates Stratified by household size and total number of vehicles

Sub-Region

Minneapolis St. PaulSuburban

MinneapolisSuburban

St.PaulMPO Core

Ring Counties, MN

Ring Counties, WI

Sampling Rate 1% 1% 1% 1% 1% 0.5% 0.5%

Zero-Vehicle HH 189 100 116 90

One-Vehicle HH 411 269 721 516 321

Two-Vehicle HH

Three-Vehicle HHFour or More Vehicle HH

Zero-Vehicle HH

One-Vehicle HH 147 95 200 189 94

Two-Vehicle HH 237 168 716 632 400 184 74

Three-Vehicle HHFour or More Vehicle HH

Zero-Vehicle HH

One-Vehicle HH 84 72

Two-Vehicle HH 226 195 147

Three-Vehicle HH 153 137 105Four or More Vehicle HH

Zero-Vehicle HH

One-Vehicle HH

Two-Vehicle HH 105 100 411 358 279

Three-Vehicle HH 195 174 121Four or More Vehicle HH 116 147 74

158

72

105

95

126

147

84

72

174 116

74

111

7674

174

72

76

Sampling Cell Targets

190

95

Two-Person HH

95

105

72Three-Person HH

One-Person HH

116

76

Four or more Person HH

95

74

72

72

72

Imbedded Design for Hard – to – Reach Populations

• Clearly define populations

• But not every group can be hard to reach or treated as such

• Identify appropriate levers; not all levers work for each group

• Use post-collection techniques sparingly (e.g., weighting)

Address Based Sampling

Cell only

Geography

Multi-Methods

Phone

Web

Mail

DesignSponsor

Legitimacy Incentives Reminders

Design Qualities of 2010-11 Minnesota HTS

• Advance letters tailored to region and sponsorship emphasized

• Recruitment by phone (matched) and web (unmatched)

• Personalized activity-based travel diary • Reminder calls made evening before scheduled

travel day (weekdays only)• Contingent incentive offered in follow-up for

specific sub-groups ($20)• Follow-up by phone, web, and mail

GPS Subsample

• 250 Total Completed Households

• Data collection consistent with main study

• 7-day travel period One day diary Diary date randomly assigned

within 7-day period• Pilot study conducted

Incentive experiment conducted

• Full GPS/diary comparison conducted by PlanTrans, Inc.

Matched

ABS

Unmatched

Phone Recruit Web Recruit

Travel PacketDeployment

7-day Travel Period

Travel Packet Returned

Diary and GPS DeviceValidation

Completed HH Incomplete HH

Study Compliance and Participation

• Thirteen percent of households recruited by web• Parity between web and mail-back of retrievals

Phone becoming less of a retrieval method Method consistent with multi-method scenario

Recruitment

Phone Web TotalRetrieval Method N % N % N %

Phone 1,563 15.1 46 2.6 1,609 13.3

Web 4,292 41.5 1,211 68.1 5,503 45.5

Mail-back/Multiple Methods 4,469 43.3 522 29.3 4,991 41.2

Total Completed 10,324 100 1,779 100 12,103 100

Total Households Recruited 22,986 87.3 3,356 12.7 26,342 100

Design Strategies to Overcome Low Responding Markets• Tailored strategies are crucial throughout the process

to overcome low responding markets

Sampling

Recruitment

Retrieval

Customized LettersPhone and Web

Targeted Sampling

Unmatched/Cell only

4+ HH 0-vehicle

Low IncomeUniversity

Non-Responders

IncentivesPhone or Web

Reminder LettersTargeted Sample

Phone, Web, MailReminder CallsReassignment

Incentives

Sampling geographic strata requires close and continual monitoring

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Recruitment at 60% Complete

Total Recruit 8,029

Percent Recruit 66.9%


Minneapolis

Suburban

St.Paul

MPO

Core

Ring Counties,

MN

Ring Counties,

WI

Zero-Vehicle HH 40% 44% 41% 49%

One-Vehicle HH 60% 55% 64% 68% 48%

Two-Vehicle HH

Three-Vehicle HH

Four or More Vehicle HH

Zero-Vehicle HH

One-Vehicle HH 81% 51% 64% 71% 61%

Two-Vehicle HH 82% 86% 85% 78% 71% 78% 74%

Three-Vehicle HH


Zero-Vehicle HH

One-Vehicle HH 32% 39%

Two-Vehicle HH 71% 56% 48%

Three-Vehicle HH 64% 76% 61%Four or More Vehicle HH

Zero-Vehicle HH

One-Vehicle HH

Two-Vehicle HH 88% 66% 76% 74% 61%

Three-Vehicle HH 69% 68% 55%Four or More Vehicle HH 69% 75% 72%

One-Person HH

PERCENT RECRUITED SAMPLE CELL

28%


Three-Person HH

126%

65%

Two-Person HH

29%

94%

58%

71%

32%

43%

119%

67% 54%

52%

45%

Table 1. Target Adherence by Recruited Households - March 2011

33%

66% 63%79%

86%

51%

75%99%

22%

59%

33% 30%

57%

26%

85%

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Retrieval at 30% Complete

Total Recruit 3,056 Percent Recruit 25.4%


Minneapolis

Suburban

St.Paul

MPO

Core

Ring Counties,

MN

Ring Counties,

WI


One-Vehicle HH 31% 29% 32% 29% 24%

Two-Vehicle HH

Three-Vehicle HH


Zero-Vehicle HH

One-Vehicle HH 28% 24% 22% 24% 20%

Two-Vehicle HH 32% 32% 34% 32% 27% 29% 27%

Three-Vehicle HH


Zero-Vehicle HH




Zero-Vehicle HH

One-Vehicle HH

Two-Vehicle HH 30% 22% 23% 19% 19%

Three-Vehicle HH 22% 24% 18%Four or More Vehicle HH 19% 21% 28% 21%

One-Person HH

16%25%

31%33%

14%Two-Person HH


3% 3%4% 6%

14%27% 24%

11% 4%

55% 49% 44% 30%

Three-Person HH

12% 11%28%

15% 26%35%

12%

29% 21%26%

Table 2. Target Adherence by Retrieved Households - March 2011

PERCENT RETRIEVED SAMPLE CELL

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Strategies for Corrections at this Point

• Incentives for under-represented cells going forward: $20 for 0-Vehicle and 4+ Person Households. Added incentives for all hhs. with incomes <$25,000.

• Additional incentives: -- Reassignment: $20 offered to recruited hhs. in under- represented cells--that did not complete. Assigned a new travel day. Refusal Conversion-- $25 to University Oversample-- $10 to GPS households that had not returned units.

• Increased reminder calls to under-represented cells• Introduced targeted sample by census tract geography for

under-represented cells

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Results of Corrective Actions on Final Retrieval


Minneapolis

Suburban

St.Paul

MPO

CoreRing Counties, MN

Ring Counties,

WI


One-Vehicle HH 137% 125% 111% 114% 97%

Two-Vehicle HH

Three-Vehicle HH


Zero-Vehicle HH

One-Vehicle HH 134% 114% 89% 93% 88%

Two-Vehicle HH 134% 134% 128% 121% 104% 107% 166%

Three-Vehicle HH


Zero-Vehicle HH




Zero-Vehicle HH

One-Vehicle HH

Two-Vehicle HH 128% 91% 88% 97% 81%

Three-Vehicle HH 81% 89% 80%Four or More Vehicle HH 67% 66% 96%

121% 104%98%

Table 3. Target Adherence by Retrieved Households - Final Delivered Sample

PERCENT RETRIEVED SAMPLE CELL

Three-Person HH

54% 33%120%

82% 107%

83%89%

43% 20%

145% 146% 151% 154%

3% 1%39% 25%

122%

76%

99%114%

One-Person HH

43%113%

88%123%

101%Two-Person HH


Geographic RepresentativenessRegional Classifications Completed ACS 2006 - 2008 Diff

N % N % %Minneapolis 1,789 14.8 158,389 11.8 -3.0

St. Paul 1,122 9.3 108,708 8.1 +1.2

Core West – Suburban Minneapolis

3,313 27.4 345,262 25.7 +1.7

Core East – Suburban St. Paul 2,922 24.1 213,200 15.9 +8.2

Core South – MPO Core 1,638 13.5 278,352 20.7 -7.2

Ring Counties, Minnesota 841 6.9 176,191 13.1 -6.2

Ring Counties, Wisconsin 478 3.9 63,977 4.8 -0.9

Total 12,103 100 1,344,079 100 -6.2

Demographic RepresentativenessHH Characteristics Completed ACS 2006 - 2008 DiffHH Size N % N % %1 3,717 30.7 377,973 28.1 +1.4

2 4,804 39.7 445,443 39.7 0

3+ 3,582 29.5 520,663 38.8 -9.3

Total 12,103 100 1,344,079 100 -7.9

Number of Vehicles N % N % %

0 483 4.0 91,586 6.8 -2.8

1 3,806 31.4 413,357 30.8 +1.4

2+ 7,814 64.6 839,136 62.5 +2.1

Total 12,103 100 1,344,079 100 +0.7

Best Practices and Lessons Learned

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Best Practices for a Representative HTS

• ABS allows inclusion of cell-only households and improves geographic targeting by key variables

• Establish legitimacy of sponsor – advance letters/postcards/website• Continual monitoring as random data collection proceeds as designed.• Continual interval data review/editing and reporting -- so that hhs. not

meeting quality standards can be replaced as data collection proceeds• Implementation of corrective actions at approximately the two-thirds

recruitment point

Results in a representative sample that can be weighted with bias minimized.

Contact Information

Laurie WargelinAbt SRBI

[email protected]

mailto:[email protected]

Best Practices Met Council Household Travel Survey (HTS) 2010-2012 May 8. 2013.

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