National Academies Press: OpenBook

Implementing the Freight Transportation Data Architecture: Data Element Dictionary (2015)

Chapter: Chapter 4 - Inventory of Freight Data Sources, Dictionaries, and Glossary Terms

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Suggested Citation:"Chapter 4 - Inventory of Freight Data Sources, Dictionaries, and Glossary Terms." National Academies of Sciences, Engineering, and Medicine. 2015. Implementing the Freight Transportation Data Architecture: Data Element Dictionary. Washington, DC: The National Academies Press. doi: 10.17226/21910.
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Suggested Citation:"Chapter 4 - Inventory of Freight Data Sources, Dictionaries, and Glossary Terms." National Academies of Sciences, Engineering, and Medicine. 2015. Implementing the Freight Transportation Data Architecture: Data Element Dictionary. Washington, DC: The National Academies Press. doi: 10.17226/21910.
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Suggested Citation:"Chapter 4 - Inventory of Freight Data Sources, Dictionaries, and Glossary Terms." National Academies of Sciences, Engineering, and Medicine. 2015. Implementing the Freight Transportation Data Architecture: Data Element Dictionary. Washington, DC: The National Academies Press. doi: 10.17226/21910.
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Suggested Citation:"Chapter 4 - Inventory of Freight Data Sources, Dictionaries, and Glossary Terms." National Academies of Sciences, Engineering, and Medicine. 2015. Implementing the Freight Transportation Data Architecture: Data Element Dictionary. Washington, DC: The National Academies Press. doi: 10.17226/21910.
×
Page 29
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Suggested Citation:"Chapter 4 - Inventory of Freight Data Sources, Dictionaries, and Glossary Terms." National Academies of Sciences, Engineering, and Medicine. 2015. Implementing the Freight Transportation Data Architecture: Data Element Dictionary. Washington, DC: The National Academies Press. doi: 10.17226/21910.
×
Page 30
Page 31
Suggested Citation:"Chapter 4 - Inventory of Freight Data Sources, Dictionaries, and Glossary Terms." National Academies of Sciences, Engineering, and Medicine. 2015. Implementing the Freight Transportation Data Architecture: Data Element Dictionary. Washington, DC: The National Academies Press. doi: 10.17226/21910.
×
Page 31
Page 32
Suggested Citation:"Chapter 4 - Inventory of Freight Data Sources, Dictionaries, and Glossary Terms." National Academies of Sciences, Engineering, and Medicine. 2015. Implementing the Freight Transportation Data Architecture: Data Element Dictionary. Washington, DC: The National Academies Press. doi: 10.17226/21910.
×
Page 32
Page 33
Suggested Citation:"Chapter 4 - Inventory of Freight Data Sources, Dictionaries, and Glossary Terms." National Academies of Sciences, Engineering, and Medicine. 2015. Implementing the Freight Transportation Data Architecture: Data Element Dictionary. Washington, DC: The National Academies Press. doi: 10.17226/21910.
×
Page 33

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26 C H A P T E R 4 4.1 Introduction Public and private agencies collect data relating to freight transport to meet their specific needs. This study identified 42 data sources, comprising 31 public sources and 11 commercially available sources (Table 4-1 and 4-2). The following details are provided from 25 of the 31 public sources: • Overview: A brief description of the data source and contents. • Coverage: The extent or degree to which data was collected, analyzed, or reported. • Availability: The time period that each data source covers and the frequency at which data is collected or updated. • Uses: A brief description of how each data source is currently being utilized as reported by the agencies. • Data Tables: A summary of identified databases and data tables for each data source and their years of availability. • Data Collection Method and Limitations: A brief summary of data collection procedures, sample design, statistical estimation, and other related data processing and quality control pro- cedures. Readers are referred to the original data source, user guides, or manuals to acquire additional information. • References: A list of web addresses to user manuals, data download ports, location of data dictionaries, and other useful or recommended reading materials. • Data Provider and Contact: Information about the data-providing agency. Limited information also is documented for the remaining six public and 11 commercial data sources. Agency reports generated from the actual data sources are excluded from the review. Some data sources were found to contain multiple databases, data tables and associated data dictionaries or glossary terms. This chapter provides additional information on how the data sources were inventoried. 4.2 Data Dictionaries and Glossary Terms Data elements from data dictionaries and glossaries similar to those shown in Figure 4-1 and Figure 4-2 were identified. Data dictionaries from 28 sources were compiled, including two commercial sources, and the total number of data elements included in the master data diction- ary for NCFRP Report 35 was 6,322. In addition, 13,554 glossary terms from 13 glossaries were compiled into a glossary for this project. 4.2.1 Definition of Terms • As used in NCFRP Report 35, the phrase data source refers to the actual name given by an agency to its data. It is important to note that a data source may contain multiple databases. For example, Inventory of Freight Data Sources, Dictionaries, and Glossary Terms

Inventory of Freight Data Sources, Dictionaries, and Glossary Terms 27 Public Freight Data Source Agency 1 Air Carrier Statistics U.S. DOT - RITA - BTS 2 Annual Survey of Manufacturers U.S. DOC - Census Bureau 3 Carload Waybill Sample Surface Transportation Board 4 Commodity Flow Survey U.S. DOT - RITA - BTS 5 County Business Patterns U.S. DOC - Census Bureau 6 EIA Data Services U.S. DOE - EIA 7 Fatality Analysis Reporting System U.S. DOT - NHTSA 8 Federal Railroad Administration Safety Database U.S. DOT - FRA 9 Foreign Trade U.S. DOC - Census Bureau 10 Freight Analysis Framework U.S. DOT - FHWA 11 Highway Performance Monitoring System U.S. DOT - FHWA 12 Pipeline and Hazardous Material Safety Administration U.S. DOT - PHMSA 13 Maritime Statistics U.S. DOT - MARAD 14 Motor Carrier Management Information System U.S. DOT - FMCSA 15 Motor Carrier Safety Measurement System U.S. DOT - FMCSA 16 National Agricultural Statistics Service USDA - NASS 17 National Highway Planning Network U.S. DOT - FHWA 18 Survey of Business Owners U.S. DOC - Census Bureau 19 Service Annual Survey U.S. DOC - Census Bureau 20 Topologically Integrated Geographic Encoding and Referencing U.S. DOC - Census Bureau 21 Transborder Freight Database U.S. DOT - RITA - BTS 22 U.S. Economic Accounts U.S. DOC - BEA 23 U.S. Waterway Data USACE - Waterborne Commerce 24 Vehicle Inventory and Use Survey U.S. DOC - Census Bureau 25 Vehicle Travel Information System U.S. DOT - FHWA Additional Public Freight Data Sources* Agency 26 Air Carrier Financial Reports U.S. DOT - RITA – BTS 27 Business Dynamic Statistics U.S. DOC - Census Bureau 28 Statistics of U.S. Businesses U.S. DOC - Census Bureau 29 Transportation Services Index U.S. DOT - RITA – BTS 30 U.S. Highway Statistics Series U.S. DOT – FHWA 31 Workforce Information Database (structure only) Analyst Resource Center BTS = Bureau of Transportation Statistics; EIA = Energy Information Administration; MARAD = United States Maritime Administration; USACE = U.S. Army Corps of Engineers; U.S. DOC = U.S. Department of Commerce. *These publicly available sources were identified but are not included in the discussions. Table 4-1. Identified public freight data sources.

Clockwise from top: FAF3, Transborder, Carload Waybill Sample, Air Carrier Statistics. Figure 4-1. Examples of available freight data element dictionaries. Commercial Freight Data Source Agency 1 Dun and Bradstreet Hoovers Database Dun and Bradstreet 2 FleetSeek Fleet Owner Magazine 3 IMPLAN Data Files IMPLAN Group LLC 4 InfoUSA InfoGroup 5 Intermodal Association of North America Data and Statistics Intermodal Association of North America 6 Lloyd’s Marine Intelligence Unit Lloyd’s List Intelligence 7 Motor Carrier Annual Report American Trucking Association 8 Port Import Export Reporting Service United Business Media Global Trade 9 State of Logistics Report Council of Supply Chain Management Professionals 10 Transearch IHS Global Insight 11 Woods and Poole Economics Woods and Poole Economics, Inc. Table 4-2. Identified commercial freight data sources.

Inventory of Freight Data Sources, Dictionaries, and Glossary Terms 29 Figure 4-2. BTS and EIA glossaries. the Freight Analysis Framework (FAF), which is treated in this guide as a data source, is made up of multiple databases (i.e., regional databases, state-level databases and a network database). A database may also have multiple tables, each containing data elements and records. Finally, over time a database may be made available in updated versions. In Figure 4.1, for example, the version of the FAF used to generate the image included at the top of the figure is FAF3). • As adopted for this report, the term data element dictionary (data dictionary) is defined in the IBM Dictionary of Computing as “a centralized repository of information about data such as meaning, relationships to other data, origin, usage, and format” (IBM 1993). A data diction- ary “describes, defines, and lists all of the data elements that are stored in a database” (General Services Administration 1996). A typical representation of a data dictionary will include infor- mation such as elements included in the database, type/format (e.g., numeric, text, alpha- numeric), description/definition of element, possible values or scope, relationship with other elements or tables, and metadata such as comments on the quality and condition of the data. Examples of data dictionaries include the FAF3, Transborder, Carload Waybill Sample, and Air Carrier Statistics dictionaries (see Figure 4-1). • As adopted for this report, the term glossary is defined in the Oxford dictionary as “an alpha- betical list of words relating to a specific subject, text, or dialect, with explanations” (Oxford Dictionaries 2014). Examples include the BTS Dictionary and EIA Data Services Glossary websites, which are shown in Figure 4-2.

30 Implementing the Freight Transportation Data Architecture: Data Element Dictionary • As adopted for this report, the term data element is defined by the Federal Standard 1037C as “a named identifier of each of the entities and their attributes that are represented in a database” (General Services Administration 1996). For each data element, associated information such as element name, type/format, description of element, example values, reference to other data tables or sources, comments, and other relevant information may be available. Based on these definitions, the basic structure of the information stored in the master data dictionary and glossary is illustrated in Figure 4-3. For each data source, the minimum required entities are the data source name, a table containing the elements, and the elements themselves. A data source may have multiple databases and tables (as shown in Table 4-3 for the glossary); data element name and definition are required. Table 4-4 provides information on the glossaries and the number of elements contained in each glossary. Tables 4-5 and 4-6 show the data element properties and their definitions as stored in the master data dictionary and glossary tables, respectively. 4.2.2 Recommended Data Types Given the variability of the data types reported in the various data element dictionaries, the study team developed a uniform set of recommended data types. The recommended data types seek to assist data users in determining how to correctly use each data element for research and analysis. The uniformly designated data types and their definitions are listed in Table 4-7. Recommended data types are specified for each data element in the master data dictionary. The field containing the recommended data types appears next to the originally reported data types, which were sometimes considered ambiguous when describing the context in which a data element can be used (see Figure 4-4). For example, a data dictionary will specify a data element field as numeric but it may differentiate whether the numbers represent a name of a place or an actual measured value. When used with the data element definitions, the recommended data types provide an additional level of clarity on how to correctly apply (or not apply) a chosen form of statistical analysis to a data element set. * required fields Figure 4-3. Data structure of master data dictionary and glossary.

Inventory of Freight Data Sources, Dictionaries, and Glossary Terms 31 Public and Commercial Data Sources Number of Tables Number of Elements 1 Air Carrier Statistics 12 504 2 Air Carrier Financial Reports 12 478 3 Annual Survey of Manufacturers 4 62 4 Border Crossing/Entry 1* 5 5 CTA Intermodal Terminals Database 2 12 6 Carload Waybill Sample 2 252 7 Commodity Flow Survey 2 18 8 County Business Patterns 7 322 9 Fatality Analysis Reporting System 18 310 10 Federal Railroad Administration Safety Database 6 503 11 Foreign Trade 32 389 12 Freight Analysis Framework 2 70 13 Highway Performance Monitoring System 2 117 14 IHS Transearch 2 30 15 Motor Carrier Management Information System 22 358 16 Motor Carrier Safety Measurement System 1* 32 17 National Agricultural Statistics Service 4* 38 18 National Ballast Information Clearinghouse Database 3* 38 19 National Corridors Analysis and Speed Tool Database 1* 21 20 North American Transborder Freight Database 5 66 21 Pipeline and Hazardous Material Safety Administration 1* 33 22 Service Annual Survey 1 28 23 Survey of Business Owners 1 198 24 Topologically Integrated Geographic Encoding and Referencing 15 483 25 U.S. Waterway Data 11 266 26 Vehicle Inventory and Use Survey 1 242 27 Vehicle Travel Information System 9 207 28 Woods and Poole Economics, Inc. 2 1240 Total 181 6,322 *Element names were extracted from web forms. Table 4-3. Data dictionaries. Public and Private Glossaries Number of Elements 1 Air Carrier Financial Report Glossary 29 2 BEA Glossary 272 3 Border Crossing/Entry Data 12 4 Commercial Vehicle Information Systems and Networks Glossary 453 5 Economic Census Definitions (Census Bureau) 65 6 EIA Glossary 2,579 7 Freight Glossary and Acronyms (FHWA) 166 8 Glossary of Shipping Terms (Maritime Administration) 832 9 IMPLAN Glossary (IMPLAN) 207 10 Intermodal Glossary (IANA) 197 11 State of Logistics Report Glossary (CSCMP) 2,461 12 Topologically Integrated Geographic Encoding and Referencing 12 13 Transportation Expressions and Transportation Acronym Guide 6,069 Total 13,354 Table 4-4. Glossaries.

32 Implementing the Freight Transportation Data Architecture: Data Element Dictionary Field Description 1 Data Source The data source name (e.g., Air Carrier Statistics, FAF, Foreign Trade, etc.). 2 Database A database contained in the data source, if available (e.g., Air Carrier Statistics has two databases: U.S. Carriers and All Carriers. See Appendix A for examples). 3 Sub-Database A sub-database of the database, if applicable (e.g., U.S. Waterway Data includes 10 databases and 11 sub-databases. See Appendix A for examples). 4 Table Each table can be considered as the “data dictionary” for a specific group of elements. 5 Data Element Name The name of the data element in the dictionary. 6 Alias Any published secondary name of the data element that slightly differs from the Data Element Name. 7 Definition A readable phrase or sentence associated with a data element within a data dictionary that describes the meaning or semantics of a data element. 8 Additional Definition Additional definition information, if available in the data dictionary. 9 Reported Data Type Data type as reported in data dictionary. Examples include character, variable character (varchar), numeric, and text. 10 Recommended Data Type A uniformly categorized set of fields (data types) for use in data elements. See Table 4-7. 11 Unit Tag Unit of measurement as determined from the data element definition. 12 Range of Values Possible values for this data element as provided in the data dictionary. 13 Comments Any additional comments concerning the data element field either made in the original data dictionary or included by the study team. 14 Primary Element Role This field is discussed in Chapter 5. 15 Secondary Element Role This field is discussed in Chapter 5. Table 4-5. Master data dictionary table. Field Description 1 Data Source The data source name (e.g., Air Carrier Statistics, FAF, Foreign Trade, etc.). 2 Database The database containing the data element, if available. 3 Glossary Term The name of the term as it appears in the glossary. Glossary terms include acronyms and abbreviations listed in the glossary. 4 Definition An explanation of the meaning of the glossary term. Table 4-6. Glossary table.

Inventory of Freight Data Sources, Dictionaries, and Glossary Terms 33 Data Type Description 1 Nominal Fields whose values exist in name only and can be counted but not measured. Examples include texts, labels, categories, highway number, city name, commodity code, zip code, and contact information. 2 Binary Fields whose values are composed of or involve two things. Examples include 0/1, true or false, and yes or no. 3 Date/Time Fields that report on the time of the day, day of the week, day of the month, year, or time period. 4 Real Number Fields whose values can be measured. Real numbers are used mainly for fields that can be represented in non-whole numbers (e.g., decimals). Examples include tonnage, miles, accidents per vehicle-mile, etc. 5 Integer Fields whose values are expressed only in whole numbers (not fractions). Examples include number of trucks, average annual truck traffic, number of containers, number of accidents, etc. 6 Currency Fields that represent monetary values. An example is the value of commodities moved in U.S. dollars. 7 Ratio Fields that report on a relationship between two numbers of the same kind. An example is the ratio of passenger miles to available seat miles, which is reported as “Load Factor” in the Air Carrier Statistics database. 8 Percentage Fields whose values are numbers or ratios expressed as a fraction of 100. Examples include percentage of truck traffic, percentage of total sales, and so forth. 9 Geometry Fields used to represent data found in GIS databases. Examples include point, line, and polygon. Table 4-7. Recommended data types. Figure 4-4. Segment of master data dictionary showing reported data type and recommended data type columns.

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TRB's National Cooperative Highway Research Program (NCFRP) Report 35: Implementing the Freight Transportation Data Architecture: Data Element Dictionary provides the findings of the research effort to develop a freight data dictionary for organizing the myriad freight data elements currently in use.

A product of this research effort is a web-based freight data element dictionary hosted by the U.S. Department of Transportation’s Bureau of Transportation Statistics (BTS).

The project web page includes a link to supporting appendices not printed with the report.

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