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CHAPTER 1 Introduction and Research Approach 1.1 Background Personal travel surveys have been conducted for over 40 years, but during that time no attempt has been made to standardize the process or to institute consistent practices of acceptable quality or reliability. Two TRB conferences--"Household Travel Surveys: New Concepts and Research Needs," in 1995 and "Information Needs to Support State and Local Transportation Decision Mak- ing into the 21st Century" in 1997 (TRB, 1996 and 1997)--and NCHRP Synthesis of Highway Practice 236: Methods for Household Travel Surveys (Stopher and Metcalf, 1996) emphasized the need for improved standardization in survey data collection. The contention is that standardi- zation of the survey process can lead to efficiencies in the planning and execution of surveys, in the assessment of data quality, and in the comparison of data between one metropolitan area and another. Over the past 40 years, many millions of dollars have been spent on collecting household or person-based data for transportation planning. For most metropolitan areas, the largest routine expenditure made from planning budgets is for the conduct of household or person travel surveys. In 1996, it was reported (Stopher and Metcalf, 1996) that the average survey cost was $400,000 for consultant services for the conduct of household travel surveys. Assuming that only half of the about 350 Metropolitan Planning Organizations (MPOs) in the United States conduct travel sur- veys within any decade, this represents a total expenditure of $74 million in a decade, or about $7.4 million per year. In spite of this huge level of activity and expenditure, there is no consistency in the process of executing surveys, nor are there recognized procedures for assessing the quality of the end product. Nevertheless, even larger sums of money are subsequently spent on develop- ing and using travel-demand models based on these data and in investments into major capital projects, implementation of far-reaching policies, and other related decisions. In some cases, the metropolitan regions that commission travel surveys do not have staff with in-depth knowledge and experience in that field. As a result, some MPOs are unable to make informed selections of consultants to perform surveys and are also unable to assess whether a use- ful product was obtained. Subsequent work in using the data for situation descriptions and mod- eling often reveals serious flaws in the data that could have been avoided if there were either a suf- ficient availability of expertise at the MPOs or a set of clearly defined procedures that could be followed by an MPO in guiding the process, selecting consultants, and assessing the work that was done. Some consultants who undertake such work are also unaware of the difficulties involved in data collection and have a lack of knowledge and expertise in various aspects of collection and assessment of the data that are apparent neither to them nor to the MPOs that may select them. They, too, could benefit from a set of standardized procedures and measures that would aid them in determining the type of survey to undertake, the methods to be implemented, and the means to assess whether the survey was being executed satisfactorily. 5