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.