U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590

Skip to content

Policy and Governmental Affairs
Office of Highway Policy Information

Home / Policy Information / Highway Performance Monitoring System (HPMS) / Appendix B

Office of Highway Policy Information
March 2014

Field Manual
Appendix B. Glossary

Adjusted Census Urban Boundary – Designated boundaries of a Census urban place or urbanized area as adjusted by responsible State and local officials in cooperation with each other, subject to the approval by FHWA (23 U.S.C. 101). Urban and rural data in HPMS must be reported in accordance with FWHA-approved adjusted boundaries.

Aggregation Business Rule – Describes how the national HPMS database and software will aggregate data as the sample view is created. Typical rules include: weighted average, predominance, proportional, or summation.

Certification of Public Road Mileage – An annual document furnished by each State to FHWA certifying the total public road length in the State as of December 31st. This document is to be signed by the Governor of the State or by his/her designee and provided to FHWA by June 1st of the year following (23 CFR 460). For additional clarification, this glossary also contains the definition of a "public road".

Collection Cycle – The period for which the data are collected; typically annually or every 2 or 3 years. This is in contrast to the HPMS reporting cycle which is annual for all data.

Comment File – A text file that accompanies the HPMS data submittal to FHWA. It explains data issues, problems, deficiencies, unusual conditions, and any significant changes from the previous HPMS submittal. It should be provided as an electronic file attached to the HPMS submittal.

Divided Highway – A multi-lane facility with a curbed or positive barrier median, or a median that is at least 4 feet in width.

English Units – The term "English" refers to the United States legislative interpretation of U.S. customary units as defined in a document prepared by the National Institute of Standards and Technology (NIST), U.S. Department of Commerce, Special Publication 330. Commonly used English units in HPMS are miles, feet, and inches.

Extent – Spatial coverage for which the data are to be reported: functional system, NHS, Sample, paved etc.

Federal-aid highways – All NHS routes and other roads functionally classified as Interstate, Other Freeways & Expressways, Other Principal Arterials, Minor Arterials, Major Collectors, and Urban Minor Collectors.

Full Extent – A population comprised of all sections of a functional system of public roads, which serves as a statistical universe for HPMS sampling and census data collection

Full Extent Data – Data that are collected in a census of a whole population, which for HPMS means data collected on all sections of a functional system of public roads.

Functional Systems– Functional systems result from the grouping of highways by the character of service they provide. The functional systems designated by the States in accordance with 23 CFR 470 are used in the HPMS.

Geographic Information System (GIS) –A system for the management, display, and analysis of spatial information.

Geospatial Data – The HPMS geospatial data provide a linear referencing system for the full extent and sample panel data on selected highway functional systems. The represented functional systems include Interstate, Other Freeways & Expressways, Other Principal Arterials, Minor Arterials, Major Collectors, Urban Minor Collectors, and all National Highway System (NHS) routes and connectors. This permits the national HPMS database to be utilized and maintained in a GIS environment.

Highway – The term highway includes roads, streets, and parkways and all their appurtenances (23 U.S.C. 101).

Linear Referencing System (LRS) – A set of procedures for determining and retaining a record of specific points along a highway. Typical methods used are milepoint, milepost, reference point, and link-node.

Metadata – Describes how data are collected or converted for reporting; explains variations in data that do not warrant the establishment of a collection requirement (e.g., type of equipment used, sampling frequency etc.)

National Ambient Air Quality Standards (NAAQS) Non-attainment Area – Any geographic region of the United States which has been designated under Section 107 of the Clean Air Act (CAA) for any pollutant for which a national ambient air quality standard exists. The national HPMS database is used for travel tracking for air quality assurance purposes in non-attainment and maintenance areas as required by EPA under the 1990 Clean Air Amendments Act (Section 187) and the Transportation Conformity Rule, 40 CFR parts 51 and 93. More specifically, these data are used primarily for establishing regional transportation-related emissions for transportation conformity purposes. Estimated travel based on these data is used for calibration and validation of base-year network travel models when required for non-attainment or maintenance areas.

National Highway System (NHS) – The National Highway System is a network of nationally significant highways approved by Congress in the National Highway System Designation Act of 1995. It includes the Interstate System and over 117,000 miles of other roads and connectors to major intermodal terminals.  All NHS routes and connectors must be identified in the HPMS.

National Network – These are the routes designated for use by dimensioned commercial vehicles under the Surface Transportation Assistance Act (STAA) of 1982 as identified in 23 CFR 658, Appendix A. Nationally designated truck routes include the Interstate System (a few sections are exempted by Federal law in Minnesota, Virginia, and District of Columbia); non-Interstate routes specifically listed in 23 CFR, Appendix A, as amended, and the other non-Interstate existing Federal-aid Primary (FAP) routes as defined prior to June 1, 1991, that STAA-dimensioned commercial vehicles may legally operate on.

PK – Primary Key – Used to indicate which fields of data within a table are to be used for establishing relationships with other tables in a database environment.

Public Road – A public road is any road or street owned and maintained by a public authority and open to public travel. [23 U.S.C. 101(a)] Under this definition, a ferryboat route is not a public road.

Roadway – The portion of a highway intended for vehicular use.

Rural Areas – All areas of a State outside of the FHWA-approved adjusted Census boundaries of small urban and urbanized areas.

Sample Panel – A collection of designated roadway sections within a system of public roads that is stable over time and is used to estimate attributes for the entire system.

Small Urban Areas – Small urban areas are defined by Census as places that have an urban population of 5,000 to 49,999 (except in the case of cities in Maine and New Hampshire) outside of urbanized areas. As a minimum, a small urban area includes any place containing an urban population of at least 5,000 as designated by Census. Designated boundaries of an urban place (or urban cluster) can be adjusted by responsible State officials subject to approval by FHWA (23 U.S.C. 101). Urban and rural data in HPMS must be reported in accordance with FHWA-approved adjusted boundaries. Area revisions as needed are expected to be submitted especially shortly after the latest Decennial (or special) Census information becomes available.

State (Codes) – The term "State" refers to any one of the 50 States, the District of Columbia, or the Commonwealth of Puerto Rico. The Federal Information Processing Standard Codes for States (FIPS PUB 5-2) are included in Appendix C.

Strategic Highway Network (STRAHNET) – The STRAHNET includes highways which are important to the United States strategic defense policy and which provide defense access, continuity, and emergency capabilities for the movement of personnel, materials, and equipment in both peacetime and war time.

Summary Data – These data consist of annual summary reports for certain data not included in the HPMS full extent and sample panel data set for the rural minor collector and local functional systems. These additional data are derived from State and local sources such as statewide highway databases, management systems, Intelligent Transportation Systems (ITS) and traffic monitoring systems, and data made available from local governments and MPOs.

Table of Potential Samples – A collection of roadway sections spanning the public road network that provides the sampling frame for selection of the Sample Panel.

Urban Areas – All urban places (or clusters) of 5,000 or more population and Urbanized areas. These are the small urban and urbanized areas within the State.

Urbanized Areas and Codes – Areas with a population of 50,000 or more, as designated by the Census. An FHWA-approved adjusted urbanized area includes the Census urbanized area plus transportation centers, shopping centers, major places of employment, satellite communities, and other major trip generators near the edge of the urbanized area, including those expected to be in place in the near future. Urbanized area codes are included in Chapter 4. For multi-State urbanized areas, each State must report HPMS information for the portion of the FHWA-approved adjusted urbanized area within its State boundary. Area revisions as needed should be submitted especially shortly after the latest Decennial (or special) Census information becomes available. New codes for new or modified areas will be issued based on Census changes.

U.S. Territories – The U.S. Territories include American Samoa, Guam, the Commonwealth of the Northern Marianas, and the Virgin Islands of the United States. The Federal Information Processing Standard Codes (FIPS PUB 5-2) are included in Appendix C.

Previous | Table of Contents | Next

Page last modified on June 22, 2015
Federal Highway Administration | 1200 New Jersey Avenue, SE | Washington, DC 20590 | 202-366-4000