{"data":{"id":"us/23-cfr-490.101","jurisdiction":"us","citation":"23 CFR 490.101","heading":"Definitions.","body":"Unless otherwise specified, the following definitions apply to this part:\nAmerican Community Survey (ACS) is a national level ongoing survey from the U.S. Census Bureau that includes data on jobs, occupations, educational attainment, transportations patterns, and other topics of the Nation's population.\nAttainment area as used in this part is defined in § 450.104 of this chapter, Transportation Planning and Programming Definitions.\nBridge as used in this part is defined in § 650.305 of this chapter, the National Bridge Inspection Standards.\nCriteria pollutant is any pollutant for which there is established a NAAQS at 40 CFR part 50. The transportation related criteria pollutants per 40 CFR 93.102(b)(1) are carbon monoxide, nitrogen dioxide, ozone, and particulate matter (PM10 and PM2.5).\nFull extent means continuous collection and evaluation of pavement condition data over the entire length of the roadway.\nHighway Performance Monitoring System (HPMS) is a national level highway information system that includes data on the extent, condition, performance, use, and operating characteristics of the Nation's highways.\nMainline highways means the through travel lanes of any highway. Mainline highways specifically exclude ramps, shoulders, turn lanes, crossovers, rest areas, and other pavement surfaces that are not part of the roadway normally traveled by through traffic.\nMaintenance area as used in this part is defined in § 450.104 of this chapter, Transportation Planning and Programming Definitions. For the purposes of this part, areas that have reached the end of their 20-year maintenance period 1 are not considered as maintenance areas.\nMeasure means an expression based on a metric that is used to establish targets and to assess progress toward achieving the established targets (e.g., a measure for flight on-time performance is percent of flights that arrive on time, and a corresponding metric is an arithmetic difference between scheduled and actual arrival time for each flight).\nMetric means a quantifiable indicator of performance or condition.\nMetropolitan Planning Organization (MPO) as used in this part is defined in § 450.104 of this chapter, Transportation Planning and Programming Definitions.\nMetropolitan Planning Area as used in this part is defined in § 450.104 of this chapter, Transportation Planning and Programming Definitions.\nNational Ambient Air Quality Standards (NAAQS) as used in this part is defined in § 450.104 of this chapter, Transportation Planning and Programming Definitions.\nNational Bridge Inventory (NBI) is an FHWA database containing bridge information and inspection data for all highway bridges on public roads, on and off Federal-aid highways, including tribally owned and federally owned bridges, that are subject to the National Bridge Inspection Standards (NBIS).\nNational Performance Management Research Data Set (NPMRDS) means a data set derived from vehicle/passenger probe data (sourced from Global Positioning Station (GPS), navigation units, cell phones) that includes average travel times representative of all traffic on each mainline highway segment of the National Highway System (NHS), and additional travel times representative of freight trucks for those segments that are on the Interstate System. The data set includes records that contain average travel times for every 15 minutes of every day (24 hours) of the year recorded and calculated for every travel time segment where probe data are available. The NPMRDS does not include any imputed travel time data.\nNonattainment area as used in this part is defined in § 450.104 of this chapter, Transportation Planning and Programming Definitions.\nNon-SOV travel is defined as any travel mode other than driving alone in a motorized vehicle (i.e., single occupancy vehicle or SOV travel), including travel avoided by telecommuting.\nNon-urbanized area means a single geographic area that comprises all of the areas in the State that are not “urbanized areas” under 23 U.S.C. 101(a)(34).\nPerformance period means a determined time period during which condition/performance is measured and evaluated to: Assess condition/performance with respect to baseline condition/performance; and track progress toward the achievement of the targets that represent the intended condition/performance level at the midpoint and at the end of that time period. The term “performance period” applies to all measures in this part, except the measures for the Highway Safety Improvement Program (HSIP) in subpart B of this part. Each performance period covers a 4-year duration beginning on a specified date (provided in § 490.105).\nReporting segment means the length of roadway that the State Department of Transportation (DOT) and MPOs define for metric calculation and reporting and is comprised of one or more travel time segments.\nTarget means a quantifiable level of performance or condition, expressed as a value for the measure, to be achieved within a time period required by the Federal Highway Administration (FHWA).\nTransportation Management Area (TMA) as used in this part is defined in § 450.104 of this chapter, Transportation Planning and Programming Definitions.\nTravel time data set means either the NPMRDS or an equivalent data set that is used by State DOTs and MPOs as approved by FHWA, to carry out the requirements in subparts E, F, and G of this part.\nTravel time reliability means the consistency or dependability of travel times from day to day or across different times of the day.\nTravel time segment means a contiguous stretch of the NHS for which average travel time data are summarized in the travel time data set.\nTruck freight bottleneck, as used in this part, is defined as a segment of roadway identified by the State DOT as having constraints that cause a significant impact on freight mobility and reliability. Bottlenecks may include highway sections that do not meet thresholds for freight reliability identified in § 490.613 or other locations identified by the State DOT. Causes may include recurring congestion, causing delays in freight movement, or roadway features that impact truck movements, such as steep grades, substandard vertical or horizontal clearances, weight restrictions, delays at border crossings or terminals, or truck operating restrictions.","path":["Title 23—Highways","CHAPTER I—FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION","SUBCHAPTER E—PLANNING AND RESEARCH","PART 490—NATIONAL PERFORMANCE MANAGEMENT MEASURES","Subpart A—General Information"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-23.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:24:50Z","sha256":"08d33b1d430875dd74ecd6f7b4c699d65c7769a23d862f1b50de4952958c563e","source_id":"us-cfr","stale":true,"prev":"us/23-cfr-appendix-d-to-subpart-a-of-part-470","next":"us/23-cfr-490.103"},"notice":"GroundRules: Original legal text. Not legal advice."}