Freight Transportation Surveys (2011)

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7 scope, data integration, proprietary and restricted-use information, cost, and existing agency guidelines. Make recommendations regarding ways to improve the • state of the practice. Identify gaps in knowledge and areas for potential • future research. Given this scope, it is important to note that although the applications of freight surveys are broad, the Project Panel cited the role of surveys in modeling as being particularly important. Subject This synthesis focuses on existing methods used to collect data on freight transportation and agency guidelines. Sev- eral different aspects of freight transportation surveys are considered: Purposes for which data are collected and the survey • methods appropriate for each purpose Survey types, including the following:• Roadside interviews – Web-based surveys – Mail-in [i.e., mail-out]/mail-back surveys – Vehicle intercept – Telephone call-in [i.e., call-out]/call-back – Personal interviews – Vehicle tracking – License plate match – Administrative data – Focus and stakeholder groups/Delphi techniques – Survey sampling issues• Regional and corridor versus statewide survey issues• Design of surveys at different levels to enable data • integration Cost of surveys and data collection• Proprietary and restricted-use information issues• Guidelines used by agencies in formulating freight • transportation surveys to meet specific data needs Gaps in knowledge and research needs, including for • guidelines. Consideration also is given to the feasibility of linking survey data with data from informatics such as roadway, on- board vehicle, and wide area sensors. CHAPTER ONE INTRODUCTION CONTEXT The efficient movement of freight is important for local, state, and national economic viability. Understanding the movement of freight and its characteristics is essential to promoting efficiency and economic development. There is a need to examine the different methods, techniques, and results of current efforts to survey and collect data on freight transportation, data that can take many forms, from classi- fied traffic counts and travel time studies to comprehensive commodity flow and origin-destination surveys. Because of the complexity of the demand for freight transportation, however, it can be challenging to collect. Several factors contribute to this complexity. For example, urban freight transportation factors include the number and varying characteristics of the decision makers, the diversity in the types of goods (i.e., commodities) carried, origin-des- tination and routing patterns, freight costs, units of measure, and the activities that take place in an urban area. The supply chain involves a number of decision makers in both the pub- lic and private sectors: the former as providers and owners of freight infrastructure and services and as regulators, and the latter as shippers, carriers, and distributors of goods. Finally, the movement of freight can involve several transportation modes, intermediate transfer and processing facilities, and jurisdictions. OVERVIEW Purpose The large range of freight survey practices reflects the com- plexity of freight demand and the multiplicity of influencing factors and supply chain participants. The purpose of this synthesis is to improve the state of the practice in freight transportation survey methods. The synthesis has four spe- cific goals: Develop a profile of the current state of the practice • in methods and techniques used to survey and collect data on freight transportation, through a community survey and literature review. Based on this profile, identify the important issues con-• cerning survey types, purpose, sample size, geographic

8 synthesis, and presents various definitions for terms that are used in the text. Chapter two discusses the method for the literature review and for the surveys, as well as the assumptions for conduct- ing the literature review, the survey, and the interviews. This chapter is not intended to be a detailed discussion, but rather to ensure that the reader understands how the information was gathered and any caveats or comments that may be asso- ciated with the information. Chapter three summarizes the state of the practice in transportation survey methods, as derived from a survey of practitioners that was conducted for this work. This chapter documents and synthesizes current practices used to collect freight transportation data, characteristics, and important issues of each survey type. Chapter four complements the practitioners’ survey results with case studies from the literature. The chapter also includes a comparison of survey techniques. Chapter five concludes the work with a series of recom- mendations for future research in the area of freight trans- portation surveys, based on the practitioners’ survey and the case studies. There are three supporting sections to the text: a list of references, a bibliography of sources and a glossary of selected terms. Finally, two appendixes complement the synthesis. Appendix A (a web-only section of this report) contains a copy of the web-based survey questionnaire with a complete tabulation of the survey results. Appendix B lists the organizations that responded to the survey. AUDIENCES This synthesis is intended to serve as a resource primarily to state DOTs and MPOs that have some or all of the following freight data collection activities: Freight transportation data are required to provide • input for transportation operations and transportation planning and investment decisions. Freight transportation data collection initiatives are • administered, either internally or externally by a consultant. Freight data are purchased from commercial sources.• Many national government agencies are involved with conducting various freight data surveys, such as the country- wide Commodity Flow Survey. These sources of data and their uses also are considered. Scope The Project Panel has defined the scope of this synthesis by the following points: The emphasis is on the road-based movement of freight; • that is, surveys of truck freight. However, it is important to note that data for other freight modes (rail, air, water, intermodal, and pipeline) also are taken into account in the survey of practitioners (see the next section, Study Process) for purposes of completeness of coverage. The synthesis examines both urban and inter-urban • surveys. The focus is on U.S. state and regional agencies, but the • synthesis also includes select national agencies, port authorities, and purveyors of commercial freight data. The synthesis focuses on U.S. practices, but also con-• siders practices in other jurisdictions. The scope of freight survey techniques considered does • not include traffic counts. The synthesis focuses on the most recent survey expe-• rience, in order to appropriately represent the prime objective of the state of the practice. However, where appropriate, reference also is made to older surveys. Study Process The synthesis focuses on the practice as opposed to academic or theoretical considerations; although the latter are noted if they were relevant. The basis of the synthesis is information that was gathered in two ways: a review of the literature and a web-based survey of state departments of transportation (DOTs), selected metropolitan planning organizations (MPOs), and selected national agencies, port and airport authorities, and commercial purveyors of freight data. Thus the synthesis primarily consid- ered the practices of state and regional planning agencies, but also considered other significant participants in U.S. freight data collection activities. It also assembles opinions and inter- pretations as well as factual information. Case study examples are used to illustrate the different approaches and best practices: these are drawn from the survey and from the literature. Finally, it is important to note that this synthesis focuses on the technical aspects of the state of the practice in freight transportation surveys. It is not intended to be judgmental with respect to the policies of individual organizations or how these organizations have used the resultant freight trans- portation data. Nor is the synthesis intended to advocate par- ticular policies or practices; rather, it attempts to present an unbiased and accurate summary of the state of the practice. ORGANIZATION This synthesis is organized into four chapters. The remain- der of chapter one identifies the intended audiences for the