Technical Appendix to NCHRP Report 571: Standardized Procedures for Personal Travel Surveys (2007)

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48 CHAPTER 4 4. Design of Survey Instruments In this chapter, those elements relating to the design of survey instruments are discussed, and proposed guidelines and standardized procedures are described. The elements are provided in the same order as shown in the preceding chapter. 4.1 I-1: MINIMUM QUESTION SPECIFICATION 4.1.1 Definition This item is concerned with establishing the minimum question content of a household travel survey, whether it is time-use, activity or trip based, in order to obtain essential information about travel, activity, demographic and vehicular attributes of the household. It is important to note that the concern here is with specifying a minimum set of questions that all surveys should include. Most, if not all, surveys will probably include additional questions beyond these. However, if this minimum set is used consistently all surveys, both the usefulness of each survey will be enhanced, and the comparability among surveys will be improved. 4.1.2 Research on Minimum Questions Achieving a set of minimum questions or a list of core survey questions, as phrased by Pratt (2003), will enable the development of standard variables and categories and allow for uniformity and, hence, comparability across data sets. Another benefit of this process is that the value of data already collected will increase while the cost of implementing the proposed standardization remains minimal. Analysis of such data may provide insight into travel behavior and therefore this information may be used in transportation planning tools. Table 20 presents a preliminary suggestion for minimum question specifications. Comparing this table with the seven metropolitan data sets, it was found that none of these data sets totally conformed to the minimum question recommendations. One metropolitan data set had 27 out of 33 items represented and this was the closest to conformity with the list in Table 20. It was observed that items H2, H3, H5, H6, P7, and A1 in Table 20 were represented in all of the data sets. The poorest representation was for the items P6, P8-P11, A10 and V1-V6. Household items were best represented in the data sets followed by activity items and personal items. Vehicular items were very poorly represented. This clearly illustrates the need for a set of minimum questions because this is an important area for which data should be collected; such data may provide insight into the travel behavior of households as well as provide information that can be used to study environmental impacts caused by particular vehicles. Table 20: Preliminary Suggested Minimum Question Specifications Category Ref. Item Description H1 Location Home address or home position in geographic terms Household H2 Type of Building Detached, semi-detached, terraced, flat, etc.

49 H3 Number of Members H4 Relationships Matrix of relationships between all members of the household H5 Income Indication of total household income (gross, annual) from all sources H6 Number of Vehicles Summary of number of vehicles from vehicle data P1 Gender P2 Year of Birth (Preferable to requesting age) P3 Commitments Work and/or student status for each person P4 Paid Jobs Number of paid positions and hours worked at each in the past week P5 Occupation Type of work done P6 Job Classification Employee, self-employed, etc. P7 Driving License Whether or not a current drivers license is held P8 Non-mobility Indication of why no out-of-home activity was performed on a survey day including work-at-home days P9 Start Location Location at the beginning of the first survey day P10 Education Level Highest level of education achieved P11 Handicap Types of mobility handicap, both temporary and permanent P12 Race11 Defined as currently measured in the U.S. Census Personal P13 Hispanic Origin1 Defined as currently measured in the U.S. Census V1 Make V2 Model V3 Body Type E.g., car, van, RV, SUV, etc. V4 Year of Production V5 Ownership of Vehicle Household/person, lease, institution Vehicle V6 Use of Vehicle Main user of vehicle and possible list of other users A1 Start Time12 A2 Activity or Purpose A3 Location Where the activity was performed, unless traveling A4 Means of Travel If activity is travel, what mode(s) was used A5 Mode Sequence Unless collected as fully segmented data A6 Group Size Number of persons traveling with respondent as a group A7 Group Membership Number of persons in the group who live in respondent’s household A8 Costs Total amount spent on tolls, fares and respondent’s share A9 Parking Amount spent to park Activity A10 Public Transit Route Name/number of bus route, train, other transit used on each segment In addition to the items in Table 20, it may be suggested that questions relating to the following issues should be included: • The housing tenure of the respondent (own or rent status: a household item); and • If traveling by private vehicle, whether the respondent was a driver or passenger (activity item). It may also be useful to determine whether the respondent possesses a cell phone and has access to the internet, and if so, whether this is at home, work or both. However, such a question is currently not considered essential for inclusion in the minimum question set. In Table 20, a household item identifying racial and cultural background was not suggested from the original sources. However, despite the controversy associated with asking questions about this item, race and ethnic origin should be included in the list. According to Pratt (2003), information on race is required to define the sample population and to conduct interviews; matching interviewers to respondents 11 All surveys shall use the U.S. Census Bureau definition of Race. 12 Only start time needs to be ascertained in a time-use or activity survey, because, by definition, the start time of an activity is the end time of the previous activity. Only the last activity should need an end time.

50 may increase response rates for CATI surveys. The data gathered on this characteristic of the household may provide insight as to why certain journeys and activities are made, e.g., home-based school trips made by the parent or the guardian. This information may also explain why one of the parents or a guardian is not part of the workforce and hence why annual household income is in the lower income bracket. Cultural differences are important to acknowledge before, during and after the data analysis process especially from an environmental justice perspective. Obtaining an adequate sample of people from different racial and income backgrounds, within the sample drawn for the household travel survey will lead to sufficient representation of minority groups and, hence, avoid sample bias. Decisions emanating from unbiased data should take into account travel patterns and needs of particular minority groups and hence address the environmental justice objective: no person or group of people shall be subjected to a disproportionate share of adverse environmental impacts resulting from a development in urban infrastructure or other policy outcome (EPA, 2004). Ethnicity, on the other hand, is not necessarily part of the characterization used in environmental justice, and there is no evidence that it has ever been used in a travel demand model, or in any form of forecasting from transportation data. However, after extensive discussions with the panel for this project, it is recommended as a question to be included in the minimum question specification. In various situations relating to environmental justice, it is being used, and its omission, when race is asked, was seen to be potentially problematic. Household income is a characteristic on which people are reluctant to give information. It was considered for inclusion in the minimum question specification, but was rejected for several reasons. First, the reluctance of people to provide it means that often as much as 20 percent of the sample may have missing income data, so that the variable often cannot be used practically in modeling or related activities. Second, phrasing the income question to gain consistent data is very difficult. In its Quarterly Survey of Income and Expenditure, the U.S. Bureau of the Census uses a battery of about 25 questions to ascertain annual household income. The average household travel survey tries to do this with one question. The result is certain to be inconsistent, In addition, it is a known fact that households will frequently misreport income, either inflating income to impress the interviewer, or deflating it, in order to avoid perceived risks of reporting of survey results to the Internal Revenue Service. Based on all of these issues, it was decided to exclude household income from the minimum question specifications. While examining the seven data sets and establishing the common questions and variables, it was noted that, for one of the data sets, a question asked about the number of licenses in the household, whereas, for the other data sets, the question asked about the number of licensed drivers in the household. Both questions ask about drivers’ licenses however one quantifies the number of licenses in the household, while the other quantifies the number of licensed drivers in the household. The difference will arise if a household member holds more than one driver’s license. The information that is of real value here is whether or not the household member has a valid driver’s license and therefore the latter question should be asked. Question wording and content is important, because the data obtained from incorrectly worded questions will not be the desired information as explained above. This topic is discussed in more detail in section 4.3. Achieving a set of minimum questions will enable the development of standard variables and categories and allow for uniformity and hence comparability across data sets. Another benefit of this process is that the value of data already collected will increase, while the cost of implementing the standard proposed remains minimal. Analysis of such data may provide insight into travel behavior and therefore this information may be used in transportation planning tools. Another issue is whether or not personal travel surveys need to collect data on the alternative transport modes, destinations, or other elements that were in the decision set of the respondent, but not chosen. This is an issue that is restricted to surveys that are conducted for the purposes of building models of travel choices. However, it is an issue that has not been addressed adequately elsewhere. It is recommended that these questions not be included in the minimum question specification. In general, current practice is not to ask questions on alternative modes and destinations, and their characteristics,

51 and there is a potential for serious burden problems in trying to do so. In many instances, the information gathered will be a matter of guesswork on the part of respondents, and it is questionable as to whether this is relevant to any model-building exercise. There may be special cases where such questions are warranted, but they should not be part of the minimum specification. A second issue is whether or not travel times, distances, and costs should be asked for in the minimum set of questions. It is again recommended that these questions should not be included in the minimum question specification. In the matter of travel times, distances, and costs, it is well known that respondents generally do not report these values accurately. For travel time, it is generally more reliable to ask the time of departure and time of arrival, and derive the travel time for this. While it is true that most people will round clock times to the nearest 5 or 15 minutes, so that the time derived will not be particularly accurate, travel times themselves will usually be rounded to the nearest 15 minutes, so that not much different accuracy is obtained from a question of elapsed time. The data from the 1996 North Central Texas Council of Governments Household Travel Survey illustrates this point quite well, as shown in Figure 4. The peaks show the 5 and 15 minute rounding very clearly. Indeed, from an analysis of the data, we find the distribution of reported minutes for the end of an activity shown in Table 21. Only 13.4 percent of respondents gave a time to the nearest minute, while 45.2 percent gave the time as on the hour or the half hour. Similar results are found in most surveys. Table 21: Distribution of Reported Activity End Times from 1996 NCTCOG Survey Reporting of Minutes for End of Activity Percent of Valid Reports Reported on the hour 29.5% Reported on 15 minutes 7.2% Reported on 30 minutes 15.7% Reported on 45 minutes 7.3% Reported as 5, 10, 20, 25, 35, 40, 50, or 55 26.9% Reported not as a multiple of 5 minutes 13.4% Further, people report times that are usually neither the real times, nor the perceived times. Rather, they are the perceived times filtered through a process of conversion to a time that the individual desires to report, either to make the choices that he or she has made seem more logical and justified, or to reflect what he or she believes the interviewer wants to hear. Travel distances are also not usually known accurately, and people can usually only report out-of-pocket costs, such as fares, tolls, and cash payments for parking, but will usually not report other aspects of cost with any reliability. For example, there are a number of reports that indicate that, when asked how much a car trip costs, around 50 percent of people report that it costs nothing. This was so widely demonstrated in the 1960s and 1970s, that most surveys since then have not asked the question. For this reason, only the out-of-pocket cost elements are recommended for the standard of minimum question specifications.

52 One additional question that should be included is to ascertain if the person would be willing to be contacted again for other transportation study projects. This question allows qualification of households that could be used for validation activities, as well as for a variety of other purposes, such as membership of a panel. It would also provide a potential pool of respondents for use in focus groups of various types. Recommendations are found in section 2.1.1 of the Final Report. 4.2 I-2: STANDARDIZATION OF CATEGORIES 4.2.1 Need for Standardization There appears to be considerable merit in defining consistent categories for those questions that are included in the minimum specifications, as well as also considering categories for some of the questions that are not specified within the minimum, but which may be included in many surveys. Probably, the most important of these are race (not including ethnicity), employment status, building/dwelling type, relationships among household members, means of travel, mobility disabilities, education levels, and activities. Lack of standardization in these categories makes it extremely difficult to make comparisons between surveys and also may preclude some elements of transfer of models from one location to another, as a result of inconsistent categorization. Furthermore, many of these variables are also supplemented from the Census, so that consistency with census definitions is also important. Table 22 shows those questions for which standard categories appear likely to be needed. In many instances, the standard categories should represent a minimum set of categories, with the possibility that more detailed categories could be created as subsets within the minimum set of categories. This may be particularly true for activity or purpose. Additional questions for which standardized categories might be developed are income and housing tenure. In these cases, we have defined standardized categories that could be used in the event that the question was included. This also ties into the issue of standardized question wordings, where Figure 4: Activity End Times from 1996 NCTCOG Survey

53 some of these more difficult questions should probably be the subject of standardized wordings to assist in a comparable design as discussed further in section 4.3. Table 22: Questions for Which Standard Categories Should Be Set Category Reference Item Household H2 Type of Building H4 Relationships Person P6 Job Classification P8 Non-mobility P10 Education Level P11 Handicap P12 Race Vehicle V3 Body Type V5 Ownership of Vehicle V7 Fuel Type Activity A2 Activity or Purpose A4 Means of Travel Across the seven data sets examined, variables that described household income, type of dwelling, type of activity, means of travel, and employment status had conflicting and overlapping categories. The problem was not so much the conflicting categories, because this could be corrected by manipulating the data (recoding) in order to get the value codes representing the same category. The real problem is the overlapping of categories e.g., an income category of $30,000, given a value code of 4, whereas the value code of 5 represents $30,000-$40,000. This cannot be corrected if the data for income is only presented as categorical data. The U.S. Bureau of the Census currently defines income in $2,500 steps from $0 through $100,000, and then defines a single group in excess of $100,000. In most personal travel surveys, it is not necessary to define income to this level of disaggregation. However, steps of $10,000 from $0 through $100,000 could be considered to represent a necessary minimum. This would allow comparability among personal transportation surveys, as well as comparability to the Decennial Census and any other surveys that use the same income categories. Income, however, does pose additional problems that result from inflation and economic growth. This means that incomes in, say, the group from $20,000 to $25,000 represent something different in 1995 than they do in 2005. The way in which this might be handled is addressed in the Section 9.5 of this Technical Appendix. While comparing the seven data sets, the variable that described the building/dwelling type also posed significant problems. It was not known whether the definition of townhouse was the same across the data sets because, in one case, townhouse was grouped with condominium, while in another data set, townhouse was grouped with duplex and triplex type housing. The definition of condominium is not clear as it is not really a housing type but rather a type of ownership. Clearly this demonstrates the need for a universal definition to be adopted. Recommended standardized categories are provided in section 2.1.2 of the Final Report.

54 4.3 I-5: STANDARDIZATION OF QUESTION WORDINGS 4.3.1 Item Description To permit comparisons across surveys conducted in different locations, at different times, it is essential that certain key questions be asked in the same manner. It is also important that the question wording or response definitions in a local survey be consistent with the wording (and definitions) used in a national survey or census, especially for variables that may serve as the basis for sampling, expansion, and checking for bias. 4.3.2 Review of Candidate Wordings Candidates for standardization of question wording include: • Variables that are used in sample stratification or expansion, and to check for potential bias: o Number of members in household; o Number of vehicles; o Income; o Owner or renter; and o Gender. • Other characteristic questions that may impact travel: o Disability. • Questions that are critical to transportation planning: o Number in traveling party; o Activity or trip purpose; and o Working at home. Other questions, such as travel costs, were reviewed but were deemed too dependent on local conditions to permit a recommendation for standardization. Number of Persons in Household: This is an essential data item that is used to classify households in most household travel survey sampling frames, to check for potential bias in the sample, to allow conversion of household rates to person rates, and, procedurally, to determine how many diaries to be sent to a given address. The average household size from the Census data is frequently used as one of the key variables to expand a survey sample to a region’s population. Thus, household size is one of the most critical data items in the entire survey. Because its charge is to have an accurate count of the entire population, the U.S. Census has a detailed definition of persons to be included and excluded from the household count. This is shown in the first row of Table 23. The remaining rows of Table 23 display the standard question wording for several of the recent larger household travel surveys. Note that travel survey practitioners have found it useful to re-iterate that the count is to include infants and small children, and to exclude college students living away and visitors. Travel surveys should follow the general form of the question wording from the NHTS, but change the word “household” to “at this address”, to prompt for inclusion of housemates: “Including yourself, how many people live at this address? Please do not include anyone who usually lives somewhere else or is just visiting, such as a college student

55 away at school. (If further clarification is needed--include infants and children, live- in domestic help, housemates, roomers)” Table 23: “Number of Persons in Household” Question Wording Survey Wording 2000 U.S. Census How many persons were living or staying in this house, apartment or mobile home on April 1, 2000. (Include in this number • Foster children, roomers or housemates • People staying here on April 1, 2000 who have no other permanent place to stay • People living here most of the time while working, even if they have another place to live DO NOT INCLUDE: • College students living away while attending college • People in a correctional facility, nursing home or mental hospital on April 1, 2000 • Armed Forces personnel living somewhere else • People who live or stay at another place most of the time) 2001 National Household Travel Survey Including yourself, how many people live in your household? Please do not include anyone who usually lives somewhere else or is just visiting, such as a college student away at school. Bay Area Travel Survey 2000 So that we know how many diaries to send – including yourself and all children, how many people live at this address? 2000-02 Southern California Travel and Congestion Study Now I need to get information about the persons in your household. How many people, including yourself, live in your household? (Includes all persons who sleep there at least 3 nights per week.) 1996 Dallas-Ft. Worth Household Travel Survey How many people live in your household, including infants and live-in domestic help? Number of Vehicles Another key variable for classifying (or stratifying in sampling) households or persons in travel surveys is the number of vehicles they have available for travel. Once again, this variable is frequently used as an expansion variable or as a check for sample bias. As shown in Table 24, there is general consensus on the standard wording of the question, but there are differences in whether two-wheeled vehicles are to be included in the count. The U.S. Census does not specify motorcycles in its definition of vehicles, although most motorcycles do weigh less than one ton so they should be included in the count. Travel survey practitioners have typically crafted the question so that only vehicles that actually run and are available for daily travel are to be included in the count. This is done specifically to exclude the non-working, hobby car parked in the garage or driveway. Note that this phrasing may lead to the average number of vehicles reported under local travel surveys (only vehicles in working order) being somewhat less than the average number reported to the Census (all vehicles). When asking for the number of vehicles, the question should be worded: “How many vehicles are owned, leased, or available for regular use by the people who currently live at this address? Please be sure to include motorcycles, mopeds and RVs. (As clarification, regular use means are in working order)” Table 24: “Number of Vehicles in Household” Question Wording Survey Primary question Motor-cycles specified? Ask about number of bicycles? 2000 U.S. Census How many automobiles, vans, and trucks of one- ton capacity or less are kept at home for use by members of your household? No No 2001 National Household Travel How many vehicles are owned, leased, or available for regular use by the people who currently live in Yes How many adult-size bicycles does your

56 Survey your household? Please be sure to include motorcycles, mopeds and RVs. household have in working order? Bay Area Travel Survey 2000 How many vehicles are available to your household? Include owned and leased cars, vans and trucks, and company vehicles available to household members for general transportation. How many motorcycles or mopeds does your household have in working order? How many bicycles, in working order, does your household have? 2000-02 Southern California Travel and Congestion Study Now, how many vehicles are presently available to members of your household? This includes all cars, vans, trucks, RVs, SUVs, motorcycles and mopeds, whether owned or leased or provided by an employer. Yes How many bicycles in working condition are available to members of your household for use in their daily travel? 1996 Dallas-Ft. Worth Household Travel Survey How many cars, pickups, trucks, vans or motorcycles are available for use by you and other members of your household? Yes No A second issue in asking about number of vehicles is whether, and then how, to ask about bicycle availability. It would be useful for travel surveys to include a separate question regarding the availability of bicycles for daily travel: “How many bicycles in working condition are available to members of your household for use in their daily travel?” Income Income, while not being one of the minimum questions, is often included and often used as a check for potential sampling bias and less frequently as a sampling or expansion variable. U.S. Census Long Form (Form D-2) asks respondents to report individual person income in dollars (as an open-ended amount) from each of the following income sources: • Wages, salary, commissions, bonuses or tips from all jobs • Self-employment-income from own non-farm business or farm business, including proprietorships and partnerships; • Interest, dividend, etc; • Social Security or Railroad Retirement; • Supplemental Security Income; • Public assistance or welfare; • Retirement or survivor or disability pensions; • Any other sources of income. However, while asking for income at the person level, the Census reports income at the household level. While the level of income source detail required by the U.S. Census is not usually necessary for travel surveys, a definition of income that is consistent with the Census definition is important. The key issue for travel surveys appears to be whether income is asked about at the person level (as in the Census and the 1996 Dallas-Ft. Worth Travel Survey), or at the entire household level (as in most other recent travel surveys). To the extent that travel models are being developed that apply at the person level, it is likely that more surveys will need to ask for person-level income. However, even for these models, household level income is important. Typical income question wordings are shown in Table 25.

57 Table 25: “Income” Question Wording Survey Person or Household Primary Question 2000 U.S. Census Person <For each person> Mark the “Yes” box for each income source received during 1999 and enter the total amount received during 1999 to a maximum of $999,999. For income received jointly, report, if possible, the appropriate share for each person; otherwise report the whole amount for only one person. 2001 National Household Travel Survey Household <In surveys like these, households are sometimes grouped according to income.> Please stop me when I get to the category that best describes your total household income, before taxes, in the past 12 months. (We want to include income from sources such as wages and salaries, income from a business or a farm, Social Security, pensions, dividends, interest, rent, and any other income received.) Bay Area Travel Survey 2000 Household Please stop me when I get to the category that best describes the total 1999 combined income for everyone living in your household: 2000-02 Southern California Travel and Congestion Study Household What was your total household income in 1999 from all sources before taxes, for all members of your household? 1996 Dallas-Ft. Worth Household Travel Survey Person and Household What was person <One’s> total annual income last year before taxes? Please read me the income range that is closest to your household’s total annual income last year before taxes: I’d like to confirm that this amount includes all members of your household, even those who are unrelated to you. Another issue in wording the income inquiry is the time period specified for the income (e.g., prior 12 months, or prior tax year). It is recommended that the question be asked about the prior year, since most U.S. respondents will know their annual income from the prior year’s tax period. Household income should be asked in the following manner: “Please stop me when I get to the category that best describes the total combined income for everyone living at this address for last year” Owner or Renter Status Owner or renter status is another variable that is often used as either a check for sample coverage bias, or as a variable to expand sample data to population data, usually Census data. The most common wordings of that question are shown in Table 26. The U.S. Census reports all household units that are not owner occupied as being renter occupied, whether cash rent was paid or not. Thus in order to use the Census as a comparison set, the question should parallel the Census wording. The question regarding owner or renter status should be worded: “Do you own or rent your home? 1 Own/buying (e.g. paying off a mortgage) 2 Rent/lease or 3 Provided by job or military” In the analysis, response option categories 2 and 3 should be combined. Table 26: “Owner or Renter Status” Question Wording Survey Question Wording 2000 U.S. Census Is this house, apartment or mobile home— • Owned by you or someone in this household with a mortgage or loan? • Owned by you or someone in this household free and clear (without a mortgage or loan)? • Rented for cash rent? • Occupied without payment of cash rent?

58 2001 National Household Travel Survey Is your home owned or rented? • Owned • Rented • Provided by job or military Bay Area Travel Survey 2000 Do you own or rent your home? • Own • Rent 2000-02 Southern California Travel and Congestion Study Do you own or rent this home? • Own/buying • Rent 1996 Dallas-Ft. Worth Household Travel Survey Do you own or do you rent your home? • Rent/lease • Own/buying (e.g., paying off a mortgage) Gender This variable is frequently used to check for sample bias. As may be seen from Table 27, the only issues are whether the question is worded to ask for a person’s “sex” or “gender,” or asks whether the person is male or female. To avoid any confusion over what is being asked, it is suggested that the question be worded: “Are you (is this person) male or female?” Table 27: “Male or Female Status” Question Wording Survey Question Wording 2000 U.S. Census What is this person’s sex? † Male † Female 2001 National Household Travel Survey Please tell me your first name, age and sex. † Male † Female Bay Area Travel Survey 2000 Are you (is this person) male or female? † Male † Female 2000-02 Southern California Travel and Congestion Study And what is (your/their) gender? † Male † Female 1996 Dallas-Ft. Worth Household Travel Survey And what is person number (1’s, 2’s, etc) gender? † Male † Female Disability It is useful to ask respondents for the presence of physical or other long-term disabilities that affect mobility. This question is often used as a check for reported immobility on the assigned travel day(s); it is less frequently used as a check for sample coverage bias. Table 28 presents common wordings of this question in travel surveys, as compared to the U.S. Census wording. A question asking about disabilities that impact travel should be asked. The wording of the question should parallel that in the U.S. Census, but should focus more specifically on the travel: “Do you have a disability or condition that has lasted 6 or more months and which makes it difficult to go outside the home alone, for example to shop or visit a doctor’s office?” If the respondent replies “yes” to having a condition that limits travel, the survey should include a follow-up question, to probe either for the specific disability (as in the Bay Area, Southern California, or Dallas surveys) or for the condition’s impact on use of travel modes (as in the NHTS).

59 Table 28: “Disability Status” Question Wording Survey Question Wording 2000 U.S. Census Does this person have any of the following conditions: 1. Blindness, deafness or a severe vision or hearing impairment 2. A condition that substantially limits one or more basic physical activities, such as walking, climbing stairs, reaching, lifting, or carrying Because of a physical, mental or emotional condition lasting 6 months or more, does this person have any difficulty in doing any of the following activities: • Learning, remembering or concentrating? • Dressing, bathing, or getting around inside the home? • (if person is 16 years old or over) Going outside the home to shop or visit a doctor’s office • (if person is 16 years old or over) Working at a job or business? 2001 National Household Travel Survey {Do you/Does SUBJECT} have a medical condition that makes it difficult to travel outside of the home? If yes, How long {have you/has SUBJECT} had this condition? Because of this condition, {have you/has SUBJECT} • reduced {your/his/her} day-to-day travel? • asked others for rides? • limited driving to daytime • given up driving altogether? • used the bus and subway less frequently? • used special transportation services such as dial-a-ride? Bay Area Travel Survey 2000 Do you (Does <insert name>) have a disability or condition that has lasted 6 or more months and which makes it difficult to go outside the home alone, for example to shop or visit a doctor’s office? If yes, what type of disability is that? • Blind/visual • Transferable wheelchair • Non-transferable wheelchair • Deaf/hearing impaired • Mentally disabled • Cane/walker • Other (Specify:) 2000-02 Southern California Travel and Congestion Study Do you /does<he/she> have a physical, mental, or other health disability that has lasted 6 or more months and which makes it difficult for<you/him/her>to go outside the home alone, for example to shop or visit a doctor's office? If yes, what type of disability is that? • Difficulty standing, walking or climbing stairs • Visually impaired/blind • Hearing impaired/deaf • Wheelchair • Require cane/walker Other 1996 Dallas-Ft. Worth Household Travel Survey Do you (does he/she) have any physical limitation that affects the type of transportation you (he/she) can use? • Difficulty standing • Difficulty climbing stairs • Visual/blind • Hearing impaired/deaf • Wheelchair • Cane/Walker • Other Number in Traveling Party The number of persons in a traveling party is usually used to determine vehicle occupancy. The 2001 NHTS used this question series to cue up a trip roster so that trips made by multiple members of the same household traveling together did not have to be reported separately. As can be seen in Table 29, the issues for question wording are:

60 1. Whether to ask for the number of persons including, or excluding the respondent; 2. Whether to ask number in traveling party for all trips, or only for those trips made by a private vehicle; and 3. Whether to ask a follow-up question regarding how many members of the traveling party were household members. Table 29: “Number in Traveling Party” Question Wording Survey When Asked Question Wording 2000 U.S. Census Asked only if mode of travel to work last week was car, truck or van How many people, including this person, usually rode to work in the car, van or truck last week? 2001 National Household Travel Survey Asked of all trips Was anyone with {you/SUBJECT} on this trip? Were any household members with {you/SUBJECT} on this trip? If Yes, Which household members? Did any non-household members go with {you/SUBJECT} on this trip, such as friends, relatives, or other people {you know/he/she knows}? If Yes, How many non-household members went on this trip with {you/SUBJECT}? [DO NOT COUNT OTHERS THAT HAPPENED TO BE USING THE SAME BUS, PLANE, TRAIN, ETC.] Bay Area Travel Survey 2000 Asked only if used private vehicle Including yourself (themselves) how many people were in the vehicle? 2000-02 Southern California Travel and Congestion Study Asked only if travel mode was drove, passenger in car/truck/van or motorcycle/moped What was the total number of people traveling with <YOU >? NOT INCLUDING THE PERSON YOU'RE ON Of those, how many were household members? 1996 Dallas-Ft. Worth Household Travel Survey Asked only if used household vehicle How many other people were in the vehicle with you (him/her), not counting yourself (himself/herself)? How many of these were members of your household (only asked if number in household was greater than one)? There do not appear to be any data that speak directly to whether including or excluding the respondent in the count of members of a traveling party makes any difference in accuracy. In the interests of consistency, the following wording would be most useful: “Including yourself, how many people were traveling with you? How many of these were household members?” If CATI is used, it is suggested that the follow-up question regarding number of household members only be asked when the household size is greater than one. At a minimum, the number in the traveling party should be asked whenever a private car, van, or truck is the mode of travel. It is a matter of local survey discretion whether to ask this question on all trips, regardless of mode. Activity or Trip Purpose To compare data across surveys, it is essential that there be common set of definitions when asking about activities or trip purposes. However, as may be seen from Table 30, there is no standardized wording, or even consistency of practice in terms of what activities are included in what might appear to be a standardized activity category.

61 Table 30: Activity or Trip Purpose Response Categories Activity or Trip Purpose 2001 National Household Travel Survey Bay Area Travel Survey 2000 2000-02 Southern California Travel and Congestion Study 1996 Dallas-Ft. Worth Household Travel Survey Household chores and personal care (child care, care of others, meal preparation) Other at-home activities Personal Care and Maintenance (Asked about trip purpose, not activities) Sleep Other at-home activities Sleep at home Social event Get/eat meal Meals Coffee/ice cream/snacks Meals at-home, take-out, restaurant, coffee, snack Eat meal (restaurant, drive through, take-out) Eat meal (restaurant, drive- thru, etc) Shopping (Away from Home) for gas, groceries, drugs, clothes, shoes, furniture, cars, etc. Shop for groceries, house wares, medicine, etc. Community Services: Includes volunteer work; attendance at meetings arranged by social, political, scouting, religious, etc. organizations; and, attending civic ceremonies and meetings. Buy goods: Groceries/clothing/ hardware store Shop for furniture, clothes, autos, appliances, etc. Shopping Buy gas Shopping (At Home) browsing by catalog, TV or Internet Shopping Buy gas Medical Medical/dental services Sick or Ill, Medical appointment Medical Visit doctor, dentist, health center, hospital Go to school as a student School (attending classes) Go to religious activity Other school activities (sports, extra-curricular) Preschool, school, college, university Education Activities Go to library: school related School or school related/College/Day Care/Homework (or other school-related work) Childcare, Day care, after school care Child care, day care, after school care Buy services: video rentals/dry cleaner/post office/car service/bank Personal Services/ Banking/Gov., e.g., barber, beauty shop, dry cleaning, banking, government services ATM, buy gas, quick stop for coffee, newspaper, etc. ATM, banking, post office, utilities Use professional services: attorney/ accountant Attend funeral/wedding Banking, Post Office, pay bills Other personal or household business (laundry, dry cleaning, shoe repair, video rental, barber/beauty shop, lawyer, accountant, broker, etc. Use personal services: grooming, haircut/nails Pet care: walk the dog/vet visits Personal/ Household Business Attend meeting: PTA/ home owners assoc./local government

62 Activity or Trip Purpose 2001 National Household Travel Survey Bay Area Travel Survey 2000 2000-02 Southern California Travel and Congestion Study 1996 Dallas-Ft. Worth Household Travel Survey Social Activities, visiting, conversation in or out of home Visit friends/relatives Visit friends or relatives (including sleeping over) Volunteer/Civic/Religiou s services or activities (meetings, volunteer work, worship, weddings, etc.) Occasional volunteer work Occasional volunteer work Community meetings, political/Civic event, public hearing Community meetings, political or civic event, public hearing, etc. Church, temple, religious meeting Church, temple, religious meeting Go to gym/exercise/play sports Recreation/ Entertainment (hobbies, exercise, TV) Fitness Activity (Playing sports, gym, bike ride) Gym/health club Rest or relaxation/vacation Relaxing/Resting (reading, listening to music, thinking) Recreational (vocational, camping. etc.) Exercise/recreation (golf, tennis, sports, jogging, walking the dog, biking, etc.) Visit friends/relatives Entertainment (watching sports, movies, dance, bar, etc.) Entertainment (movies, spectator sports, museum, etc.) Go out/hang out: entertainment/theatre/spo rts event/go to bar Social/ Recreational Visit public place; historical site/museum/ park/library Go work Work or Work Related, in or out of home Work (including regular scheduled volunteer work) Work (including regularly scheduled volunteer work) Return to work Attend business meeting/trip Work-Related (sales call, meeting, errand, etc.) Work-related (sales calls, meetings, errands, etc.) Work or Work Related Other work related Working at Home Working at home (related to main or second job) Work at home Travel Driving, Riding, Walking, Biking, Flying Traveling Pickup Someone Pick-Up/Drop Off Passenger Pick up someone or get picked up Pick up someone or get picked up Take And Wait Drop off someone or get dropped off Drop off someone or get dropped off Transport Someone Drop Someone Off Changed Transportation Mode Not a separate activity Changed type of transportation Change mode of transportation Wait for/get on vehicle Leave/get off vehicle

63 Activity or Trip Purpose 2001 National Household Travel Survey Bay Area Travel Survey 2000 2000-02 Southern California Travel and Congestion Study 1996 Dallas-Ft. Worth Household Travel Survey Accompanying someone Asked elsewhere to cue trip roster With another person at their activity out of home Be with another person at their activity Other Activities Non-Work (non- shopping) Internet use (e- mail, browsing, games) Some of the critical consistency issues are: • In asking for work or work-related activities, it is essential to use the same definition of work as used in the census, if the intention is to later on compare number of workers per household from the survey to the population. The question used by the U.S. Census to classify respondents as workers is: “Last week, did this person do any work for either pay or profit?” For travel survey designers, this means that the response options should permit a clear delineation between paid and unpaid work such as regular volunteering and working at home. • In some surveys, the home address is used to distinguish between those activities that may occur in or out of the home (e.g., meals, work). In others, there are separate response options for activities that could be performed either at or away from home, such as meals, work, shopping (using the Internet). • There is no agreement as to which activities should be included in the general categories of personal/household business, social activities, and recreational/entertainment. It should be noted that much of the practice in enumerating activities has to do with which activities the survey designer feels are most likely to be overlooked if they are not listed separately. The often-listed activity of “Buying gas” is an example. In the absence of any transportation-related taxonomy for classifying activities, it is recommended that the categories defined in Section 8.4 of this Technical Appendix be used as the standardized categories. For work or work-related activities, volunteer work should be specifically excluded from the definition. When asking for activities, a category “Other at-home activities” should always be included. Activities that could be performed either at or away from home, such as meals, work, shopping (using the Internet) could be asked for separately. To provide comparability across surveys, it is recommended that the activity or trip purpose categories of personal/household business and social/recreational be defined as follows: • Personal/Household Business: Includes buying or availing of services such as video rentals, dry cleaners, post office, car service, bank, ATM, personal services such as barber/beauty shop, government services such as post office or utilities, professional services such as lawyer, accountant, stock broker; • Social and Communication: Includes talking or conversing in-person or by telephone or via the Internet; visiting friends and relatives, participating in community or cultural events; and, visiting entertainment and cultural venues; • Community Services: Includes volunteer work; attendance at meetings arranged by social, political, scouting, religious, etc. organizations; and, attending civic ceremonies and meetings; and • Recreation and Leisure: Includes playing sports; exercise; walking for leisure (including walking the dog); reading; watching TV/videos; and surfing the Internet.

64 Working at Home As noted earlier in this Technical Appendix, the issue of successfully identifying home-based work has emerged as an issue in many travel surveys. As shown in Table 30, there have been many different approaches used to assess home-based work. Pratt (2000) suggests using a two-fold methodology that includes: 1) phrasing the questions in objective terms so that the responses can be compared across data sets; and, 2) adding questions to existing periodic surveys. She suggests that the key variables necessary to identify work at home are: • The hours/times of work: o During normal business hours (self-defined); o After-hours; o On week-ends; and o Trips interspersed with work at home. • Clarification that work at home is meant to be work for pay or profit; • Including a question(s) about a second job or home-based business, because working at home is strongly associated with these; • Including among job classification categories separate options for employee, self-employed and contractor status; and • Asking all respondents about work at home, including those who are retired, homemakers or part-time workers (the skip patterns in CATI should not automatically exclude certain persons). Pratt also suggests that because an advanced degree, higher income, use of technology and the occupations of manager, professional or sales are strongly associated with home-based work, the items education, income, occupation, and technology ownership are useful to include in surveys. All of these are indicators that may be derived from post-survey analysis, if the questions about work include clarification that what is meant is work for pay or profit, and questions about multiple jobs are included. Recommended standardized wordings are provided in section 2.1.3 of the Final Report.