KY Module 2Household Travel SurveysChapter 6 of TS Manual

Survey Planning

• Agency coordination– Other agencies who rely on local modeling

effort– Notification of law enforcement agencies.

• Critical data elements– E.g. SCAG—transit users, and usage of toll

facilities

Unit of Analysis

• Household?• Address?• Person?• Vehicle?

• What is a TRIP? • What is an ACTIVITY? • What is a STOP? • What is a TOUR?

Typical process for current household travel/activity survey implementation

• Advance letter• Telephone recruitment (RDD sample)

– Include a few characteristics• Mail out diary package• Telephone retrieval (limited web retrieval)• Thank you postcard or letter

The Death of RDD?• Problems with RDD

– Low response rates– Will new laws reduce telemarketing so that

people will be less reluctant to answer the phone?

– Cell phones are not in the RDD frame. 5-7% of hhlds with cell phone only, with young adults being most likely.

– 2.4% of hhlds in U.S. without phones. (2.0% in metropolitan areas, mostly likely renters)

Alternatives to RDD

• Getting a good address frame• 10-15% “undeliverable” rate• What % of addresses are missing?

(apartment complexes, new housing)• Can you supplement an address frame with

employer-provided lists?

Respondent materials:Section 6.6 in the TS Manual

• Check reading level, 8th is OK, but 6th grade is better!

• Pre-notification letter• Brochure• Diary materials• Reminders• Thank you

Pre-notification letter and informational brochure

• Letter: TS Manual Pages 6-133, 6-136 • Brochure: TS Manual Page 6-138• NHTS 2001 letter and brochure

Diary design

• People will NOT read instructions!• Single sheet or booklet• Vertical or horizontal• All of the questions or some of the

questions, if telephone retrieval• fjfjf

Let’s look at some!

• Las Cruces• Chattanooga• Charlotte• Tucson• SF Bay Area• SCAG• NHTS

Use a focus group if you try something new!

Incentives for respondents?

• The best motivation is the belief that the results will be used, and will influence their lives in a positive manner.

• Small, cash, pre-paid• Lottery• Gifts (often not perceived as incentive)• Choice, including donation to local service

agency

The respondent is the “customer”

• Treat them well.• Personalization.• Use the method that is convenient for the

respondent.• Brog method to assign ONE contact person,

so that person’s name is on the initial letter, and they make the phone calls, etc.

Field implementation• Pre-testing and Pilot surveys:

– TS Manual Section 6.7

Monitoring the survey process• Help develop the interviewer training

materials, especially local knowledge (Place names, company names and nicknames)

• Participate in the training• Make sure that “role playing” is included.• Listen to the interviews (if phone)• Provide materials to incentivize the

interviewers.

Data Cleaning

• Do not underestimate the time and effort needed for this task. Do not expect your survey contractor to do all the work!

Data cleaning

• Check geocoding vs. actual address• Check travel speed and mode.• Check TAZ/TAZ pairs and speeds• Check for people traveling together.• Check for final return trips to home.

Data analysis

Response Rate

• Calculate using CASRO or AAPOR standards– Can be as high as 65% response to simple

survey of persons.– Can be as low as 20% response to complex

activity diary of households.

What do we know about non-respondents?

• Low-income households and households who are renters. (relevance)

• Young men, aged 18-24 • Households without vehicles (relevance)• Households with 4+ persons (burden)• Very high income households (never home)

Ideas to improve response?

Ideas to improve response?

• Ask fewer questions. Use GPS as a passive data collection method.

• Ask fewer questions. Use specialized surveys in place of all questions for all people.

• Give respondents more choice on how and when to participate.

Non-response follow-up studies

• Even if you have a low response rate, if the sample is not biased, your results should be fine.

• However, we know from experience that our sample is somewhat biased, especially at the income tails.

• What we don’t know is how this bias affects our measures of travel and mobility.

Non-response follow-up surveyssee A1D10 webpage

• DRCOG mail-out/mail-back experiment– Small cash incentive included in envelope– Very brief one-page survey– Special survey of hhlds without telephones

• NCHRP 08-37 experiment (Spring 2003)• Tony Richardson work in Australia

– Non-responders are more like early responders, late responders report fewer trips.