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Policy Information

Footnotes

In this section, the reader will find footnotes that are too long to be displayed easily with the tables that normally could be displayed on one page if the footnotes were not included in that page. Included are footnotes related to the International section above.

HM-10: Public Road Length Miles By Ownership

1/ Prior to 1999, municipal was included with other jurisdictions.

2/ Includes State park, State toll, other State agency, other local agency and other roadways not identified by ownership.

3/ Roadways in Federal parks, forests, and reservations that are not part of the State and local highway systems.

4/ Excludes 788 miles of Federal agency owned roads.

HM-12: Public Road Length Miles By Type Of Surface And Ownership/Functional System National Summary

1/ Includes the 50 States, the District of Columbia and Puerto Rico. Some differences from other tables may be noted because these are estimated from sample and summary data; samples entirely on structures are not included. Indiana excludes 788 miles of Federal agency owned roads.

2/ Paved includes the following categories: Low type-- an earth, gravel, or stone roadway which has a bituminous surface course less than 1" thick suitable for occasional heavy loads; Intermediate Type-- a mixed bituminous or bituminous penetration roadway on a flexible base having a combined surface and base thickness of less than 7"; High-Type Flexible-- a mixed bituminous or bituminous penetration roadway on a flexible base having a combined surface and base thickness of 7" or more; also includes brick, block, or combination roadways; High-Type Composite-- a mixed bituminous or bituminous penetration roadway of more than 1" compacted material on a rigid base with a combined surface and base thickness of 7" or more; High-Type Rigid— a Portland Cement Concrete roadway with or without a bituminous wearing surface of less than 1".

3/ Prior to 1999 included other state agency roads.

HM-14: Federal-Aid Highway Length Miles By Ownership

1/ Prior to 1999, municipal was included with other jurisdictions.

2/ Includes State park, State toll, other State agency, other local agency, and roadways not identified by ownership.

3/ Roadways in Federal parks, forests, and reservations that are not part of the State and local highway systems.

4/ Excludes 788 miles of Federal agency owned roads.

HM-15: Federal-Aid Highway Length Miles By System

1/ Excludes 788 miles of Federal agency owned roads.

HM-16: Public Road Length Miles By Ownership And Federal-Aid Highways National Summary

1/ Includes the 50 States, the District of Columbia, and Puerto Rico. Indiana excludes 788 miles of Federal agency owned roads.

2/ Prior to 1999, municipal was included with other jurisdictions.

HM-18: Public Road Length Miles By Functional System And Federal-Aid Highways National Summary

1/ Includes the 50 States, the District of Columbia and Puerto Rico. Indiana excludes 788 miles of Federal agency owned roads.

HM-20: Public Road Length Miles By Functional System

1/ Excludes 788 miles of Federal agency owned roads.

HM-30: National Highway System Length Miles Open And Not Open To Traffic

1/ Excludes 788 miles of Federal agency owned roads.

HM-31: Federal-Aid Highway Length Miles By Type Of Surface

1/ Some differences from other tables may be noted because these are estimated from sample data; samples entirely on structures are not included.

2/ Paved includes the following categories: Low Type-- an earth, gravel or stone roadway which has a bituminous surface course less than 1" thick--suitable for occasional heavy loads; Intermediate Type-- a mixed bituminous or bituminous penetration roadway on a flexible base having a combined surface and base thickness less than 7"; High-Type Flexible-- a mixed bituminous or bituminous penetration roadway on a flexible base with a combined surface thickness of 7" or more; also includes brick, block or combination roadways; High-Type Composite-- a mixed bituminous or bituminous penetration roadway of more than 1" compacted material on a rigid base with a combined surface and base thickness of 7" or more; High-Type Rigid-- a Portland Cement Concrete roadway with or without a bituminous wearing surface of less than 1." Interstate data shown does not include Low and Intermediate Type.

3/ Excludes 788 miles of Federal agency owned roads.

HM-33: Federal-Aid Highway Length Miles By Lane Width

1/ Some differences from other tables may be noted because these are estimated from sample data and samples entirely on structures are included.

2/ Excludes 788 miles of Federal agency owned roads.

HM-35: Federal-Aid Highway Length Miles By Traffic Lanes And Access Control

1/ Some differences from other tables may be noted because these are estimated from sample data and samples entirely on structures are not included. Differences may exist from prior years due to the redefinition of divided and undivided roadways in 1999.

2/ Includes 3-lane roadways, one-way streets, undivided multi-lane highways, etc. for Interstate, includes some 2-lane roadways.

3/ Excludes 788 miles of Federal agency owned roads.

HM-36: Federal-Aid Highway Length Miles By Traffic Lanes And Access Control National Summary

1/ Includes the 50 States, the District of Columbia, and Puerto Rico. Indiana excludes 788 miles of Federal agency owned roads.

2/ Some differences from other tables may be noted because these are estimated from sample data and do not include samples entirely on structures.

3/ Differences may exist from prior years due to the redefinition of divided and undivided roadways in 1999.

HM-37: Federal-Aid Highway Length Miles By Average Daily Traffic Volume

1/ Some differences from other tables may be noted because these are estimated from sample data and samples entirely on structures are included.

2/ Excludes 788 miles of Federal agency owned roads.

HM-39: Federal-Aid Highway Length Miles By Lane Width, Access Control, And Average Daily Traffic Volume National Summary

1/ Includes the 50 States, the District of Columbia, and Puerto Rico. Some differences from other tables may be noted because these are estimated from sample data and do not include samples entirely on structures. Indiana excludes 788 miles of Federal agency owned roads.

2/ Differences may exist from prior years due to a redefinition of divided and undivided roadways in 1999.

HM-40: National Highway System Road Length Miles By Ownership

1/ Prior to 1999, municipal was included with other jurisdictions.

2/ Includes State park, State toll, other State agency, other local agency, and other roadways not identified by ownership.

3/ Roadways in Federal parks, forests, and reservations that are not part of the State and local highway systems.

4/ Excludes 788 miles of Federal agency owned roads.

HM-41: National Highway System Length Miles By Functional System

1/ Excludes 788 miles of Federal agency owned roads.

HM-42: National Highway System Length Miles By Volume-Service Flow Ratio

1/ In 2001, updated capacity (service flow) calculation procedures were instituted in the HPMS data reporting process. The procedures are based on the Highway Capacity Manual 2000, published by the Transportation Research Board. For multilane facilities volume-service flow ratio is determined by dividing the peak traffic in the peak direction by the capacity. For all other facilities the ratio is determined by dividing the peak traffic by the capacity. Peak traffic is estimated as AADT *K, where K is the design hour volume (30th highest hour) as a percent of AADT. Some differences from other tables may be noted because these are estimated from sample data and do not include samples entirely on structures.

2/ Excludes 788 miles of Federal agency owned roads.

HM-43: National Highway System Lane-Length Lane-Miles By Functional System

1/ Rural minor collector and rural/urban local functional system lane miles estimated by FHWA assuming two as the number of lanes.

2/ Excludes 788 miles of Federal agency owned roads.

HM-44: National Highway System Travel Annual Vehicle-Miles By Functional System

1/ Travel for all systems are FHWA estimates based on State provided HPMS data.

2/ Excludes 788 miles of Federal agency owned roads.

HM-47: National Highway System Length Miles By Measured Pavement Roughness

1/ Data are reported as the International Roughness Index (IRI) in inches per mile. Reference: World Bank Technical Paper Number 46, 1986. Lower IRI represents smoother riding roadways. To obtain a comprehensive assessment of pavement condition, additional measures of pavement distress are needed.

2/ May include sections entirely on structures and unpaved miles.

3/ Excludes 788 miles of Federal agency owned roads.

HM-48: Federal-Aid Highway Lane – Length Lane-Miles By System

1/ May see differences from prior years, starting in 1999, number of lanes is coded for all systems except rural minor collector and rural/urban local. Rural minor collector and rural/urban local functional system lane-miles estimated by FHWA assuming two as the number of lanes.

2/ Excludes 788 miles of Federal agency owned roads.

HM-49: Strategic Highway Corridor Network (STRAHNET) Length Miles By Interstate And Non-Interstate

1/ The STRAHNET includes highways which are important to the United States strategic defense. They provide defense access, continuity, and emergency capabilities for the movement of personnel, materials, and equipment.

2/ Excludes 788 miles of Federal agency owned roads.

HM-50: Functional System Length Miles By Ownership

1/ Prior to 1999, municipal was included with other jurisdictions.

2/ Includes State park, State toll, other State agency, other local agency, and roadways not identified by ownership.

3/ Roadways in Federal parks, forest, and reservations that are not a part of the State and local highway systems.

4/ Excludes 788 miles of Federal agency owned roads.

HM-51: Functional System Length Miles By Type Of Surface

1/ Some differences from other tables may be noted because these values are estimated from sample data and do not include samples entirely on structures.

2/ Paved includes the following categories: Low Type-- an earth, gravel, or stone roadway which has a bituminous surface course less than1" thick--suitable for occasional heavy loads: Intermediate Type-- a mixed bituminous or bituminous penetration roadway on a flexible base having a combined surface and base thickness of less than 7"; High-Type Flexible-- a mixed bituminous or bituminous penetration roadway on a flexible base with a combined surface thickness of 7" or more; also includes brick, block, or combination roadways; High-Type Composite-- a mixed bituminous or bituminous penetration roadway of more than 1" compacted material on a rigid base with a combined surface and base thickness of 7" or more; High-Type Rigid-- a Portland Cement Concrete roadway with or without a bituminous wearing surface of less than 1". Interstate data shown does not include Low and Intermediate Type.

3/ Excludes 788 miles of Federal agency owned roads.

HM-53: Functional System Length Miles By Lane Width

1/ Some differences from other tables may be noted because these are estimated from sample data; samples entirely on structures are included.

2/ Excludes 788 miles of Federal agency owned roads.

HM-55: Functional System Length Miles By Traffic Lanes And Access Control

1/ Some differences from other tables may be noted because these are estimated from sample data; samples entirely on structures are not included.

2/ Differences may exist from prior years due to the redefinition of divided and undivided roadways in 1999.

3/ Includes 3-lane roadways, one-way streets, multi-lane 4-lane highways, etc.; for Interstate includes 2-lane roadways.

4/ Excludes 788 miles of Federal agency owned roads.

HM-57: Functional System Length Miles By Average Daily Traffic Volume

1/ Some differences from other tables may be noted because these values are estimated from sample data; samples entirely on structures are included.

2/ Excludes 788 miles of Federal agency owned roads.

HM-59: Functional System Length Miles By Lane Width, Access Control And Average Daily Traffic Volume National Summary

1/ Includes the 50 States, the District of Columbia and Puerto Rico. Some differences from other tables may be noted because these are estimated from sample data; does not include samples entirely on structures. Indiana excludes 788 miles of Federal agency owned roads.

2/ Differences may exist from prior years due to the redefinition of divided and undivided roadways in 1999.

HM-60: Functional System Lane-Length Lane-Miles

1/ May see differences from prior years, stating in 1999, number of lanes is coded for all systems except rural minor collector and rural/urban local.

2/ Rural minor collector and rural/urban local functional system lane miles estimated by FHWA assuming two as the number of lanes.

3/ Excludes 788 miles of Federal agency owned roads.

HM-61: Functional System Length Miles By Volume-Service Flow Ratio

1/ In 2001, updated capacity (service flow) calculation procedures were instituted in the HPMS data reporting process. The procedures are based on the Highway Capacity Manual 2000, published by the Transportation Research Board. For multilane facilities volume-service flow ratio is determined by dividing the peak traffic in the peak direction by the capacity. For all other facilities the ratio is determined by dividing the peak traffic by the capacity. Peak traffic is estimated as AADT *K, where K is the design hour volume (30th highest hour) as a percent of AADT. Some differences from other tables may be noted because these values are estimated from sample data and do not include samples entirely on structures.

2/ Excludes 788 miles of Federal agency owned roads.

HM-62: Average Daily Traffic Per Lane On Principal Arterials

1/ Excludes 788 miles of Federal agency owned roads.

HM-63: Functional System Length Miles By Measured Pavement Roughness/Present Serviceability Rating

1/ Some States elect to report International Roughness Index (IRI) for these systems; some report IRI for some sections and PSR for some sections. Some differences from other tables may be noted because these are estimated from sample data.

2/ Data are reported as the IRI in inches per mile. Reference: World Bank Technical Paper Number 46, 1986. Lower IRI represents smoother riding roadways; to obtain a comprehensive assessment of pavement condition, additional measures of pavement distress are needed.

3/ The "Present Serviceability Rating" (PSR) is a subjective, primarily ride-based system adapted from the "AASHO ROAD TESTS" conducted in the late 1950’s and early 1960’s. Reference: Highway Research Board Special Report 61E, 1962. The PSR values range from 0.1 to 5.0; higher PSR values represent smoother riding roadways.

4/ Excludes 788 miles of Federal agency owned roads.

HM-64: Functional System Length Miles By Measured Pavement Roughness

1/ Data are reported as the International Roughness Index (IRI) in inches per mile. Reference: World Bank Technical Paper Number 46, 1986. Lower IRI represents smoother riding roadways; to obtain a comprehensive assessment of pavement condition, additional measures of pavement distress are needed.

2/ May include sections entirely on structures and unpaved miles.

3/ Estimated from sample data.

4/ Excludes 788 miles of Federal agency owned roads.

HM-66: Measured Pavement Roughness

HPMS Reporting Details

1/ Information in this table is intended to represent State data collection and HPMS reporting practices as submitted to FHWA and may not necessarily reflect practices used for other State purposes.

2/ The outside lane is typically the rightmost lane on multi-lane facilities in the direction of travel.

3/ NB=Northbound, SB=Southbound, EB=Eastbound, WB=Westbound. Ascending=direction of increasing or ascending milepoints.

HM-71: Urbanized Areas Miles And Daily Vehicle-Miles Of Travel

1/ A "Federal-Aid Urbanized Area" is an area with 50,000 or more persons that at a minimum encompasses the land area delineated as the urbanized area by the Bureau of the Census. Urbanized areas which have been combined with others for reporting purposes are not shown separately. Areas are sorted by population. The Illinois portion of Round Lake Beach-McHenry-Grayslake has been reported with Chicago. 2007 population data used for Indiana.

HM-72: Urbanized Areas Selected Characteristics

1/ A "Federal-Aid Urbanized Area" is an area with 50,000 or more persons that at a minimum encompasses the land area delineated as the urbanized area by the Bureau of the Census. Urbanized areas which have been combined with others for reporting purposes are not shown separately. Areas are sorted by population. The Illinois portion of Round Lake Beach-McHenry-Grayslake has been reported with Chicago. Indiana excludes 788 miles of Federal agency owned roads. 2007 population data used for Indiana.

2/ "DVMT" stands for "Daily Vehicle-Miles Traveled."

3/ Lane-miles estimated by FHWA.

HM-80: State Highway Agency-Owned Public Roads Miles By Functional System

1/ Includes roadways owned by the State highway agency. Excludes roadways owned by State toll, State park and other State agencies.

2/ Excludes 788 miles of Federal agency owned roads.

HM-81: State Highway Agency-Owned Public Roads Rural And Urban Miles; Estimated Lane-Miles And Daily Travel

1/ Includes roadways owned by the State highway agency. Excludes roadways owned by State toll, State park and other State agencies.

2/ Statewide totals for miles, lane-miles, and travel are found in tables HM-20, HM‑60 and VM-2 (annual VMT), respectively.

3/ May see differences from prior years; starting in 1999, number of lanes is coded for all systems except rural minor collector and rural/urban local.

4/ DVMT (Daily Vehicle-Miles Traveled) is in thousands.

5/ AADT means Annual Average Daily Traffic. AADT/Lane is a statewide average.

6/ Excludes 788 miles of Federal agency owned roads.

VM-2: Functional System Travel Annual Vehicle-Miles

1/ Travel for the rural minor collector and rural/urban local functional systems is estimated by the States based on a model or other means and provided to the FHWA on a summary basis. Travel for all other systems are estimated from State-provided data in the Highway Performance Monitoring System.

2/ Excludes 788 miles of Federal agency owned roads.

3/ State has revised their adjusted urbanized area boundaries and/or functional classifications.

VM-3: Federal -Aid Highway Travel Annual Vehicle-Miles

1/ Travel for the rural minor collector and rural/urban local functional systems is estimated by the States based on a model or other means and provided to the FHWA on a summary basis. Travel for all other systems are estimated from State-provided data in the Highway Performance Monitoring System.

2/ Excludes 788 miles of Federal agency owned roads.

3/ State has revised their adjusted urbanized area boundaries and/or functional classifications.

Metric Section Footnotes

HM-10M: Public Road Length Kilometers By Ownership

1/ Due to conversion from English to metric units and to rounding, individual cell values may not agree with corresponding mileage table cell values.

2/ Prior to 1999, municipal was included with other jurisdictions.

3/ Includes State park, State toll, other State agency, other local agency, and other roadways not identified by ownership.

4/ Roadways in Federal parks, forests, and reservations that are not part of the State and local highway systems.

5/ Excludes 1,268 kilometers of Federal agency owned roads.

HM-12M: Public Road Length Kilometers By Type Of Surface And Ownership/Functional System National Summary

1/ Includes the 50 States, the District of Columbia and Puerto Rico. Some differences from other tables may be noted because these are estimated from sample and summary data; samples entirely on structures are not included. Due to conversion from English to metric units and to rounding, individual cell values may not agree with corresponding mileage table cell values. Indiana excludes 1,268 kilometers of Federal agency owned roads.

2/ Paved includes the following categories: Low Type-- an earth, gravel, or stone roadway which has a bituminous surface course less than 1" thick" suitable for occasional heavy loads; Intermediate Type-- a mixed bituminous or bituminous penetration roadway on a flexible base having a combined surface and base thickness of less than 7"; High-Type Flexible-- a mixed bituminous or bituminous penetration roadway on a flexible base having a combined surface and base thickness of 7" or more; also includes brick, block, or combination roadways; High-Type Composite-- a mixed bituminous or bituminous penetration roadway of more than 1" compacted material on a rigid base with a combined surface and base thickness of 7" or more; High-Type Rigid-- a Portland Cement Concrete roadway with or without a bituminous wearing surface of less than 1".

3/ Prior to 1999 included other State agency roads.

HM-14M: Federal-Aid Highway Length Kilometers By Ownership

1/ Due to conversion from English to metric units and to rounding, individual cell values may not agree with corresponding mileage table cell values.

2/ Prior to 1999, municipal was included with other jurisdictions.

3/ Includes State park, State toll, other State agency, other local agency, and roadways not identified by ownership.

4/ Roadways in Federal parks, forests, and reservations that are not part of the State and local highway systems.

5/ Excludes 1,268 kilometers of Federal agency owned roads.

HM-15M: Federal-Aid Highway Length Kilometers By System

1/ Due to conversion from English to metric units and to rounding, individual cell values may not agree with corresponding mileage table cell values.

2/ Excludes 1,268 kilometers of Federal agency owned roads.

HM-16M: Public Road Length Kilometers By Ownership And Federal-Aid Highways National Summary

1/ Includes the 50 States, the District of Columbia, and Puerto Rico. Due to conversion from English to metric units and rounding, individual calls may not agree with corresponding mileage table cell values. Indiana excludes 1,268 kilometers of Federal agency owned roads.

2/ Prior to 1999, municipal was included with other jurisdictions.

HM-18M: Public Road Length Kilometers By Functional System And Federal-Aid Highways National Summary

1/ Includes the 50 States, the District of Columbia and Puerto Rico. Due to conversion from English to metric units and to rounding, individual cell values may not agree with corresponding mileage table cell values. Indiana excludes 1,268 kilometers of Federal agency owned roads.

HM-20M: Public Road Length Kilometers By Functional System

1/ Due to conversion from English to metric units and to rounding, individual cell values may not agree with corresponding mileage table cell values.

2/ Excludes 1,268 kilometers of Federal agency owned roads.

HM-30M: National Highway System Length Kilometers Open And Not Open to Traffic

1/ Due to conversion from English to metric units and to rounding, individual cell values may not agree with corresponding table cell values.

2/ Excludes 1,268 kilometers of Federal agency owned roads.

HM-36M: Federal-Aid Highway Length Kilometers By Traffic Lanes And Access Control National Summary

1/ Includes the 50 States, the District of Columbia, and Puerto Rico. Due to conversion from English to metric units and to rounding, individual cell values may not agree with corresponding mileage table cell values. Indiana excludes 1,268 kilometers of Federal agency owned roads.

2/ Some differences from other tables may be noted because these are estimated from sample data and to not include samples entirely on structures.

3/ Differences may exist from prior years due to the redefinition of divided and undivided roadways in 1999.

HM-50M: Functional System Length Kilometers By Ownership

1/ Due to conversion from English to metric units and to rounding, individual cell values may not agree with corresponding mileage table cell values.

2/ Prior to 1999, municipal was included with other jurisdictions.

3/ Includes State park, State toll, other State agency, other local agency, and roadways not identified by ownership.

4/ Roadways in Federal parks, forests, and reservations that are not a part of the State and local highway system.

5/ Excludes 1,268 kilometers of Federal agency owned roads.

HM-60M: Functional System Lane-Length Lane-Kilometers

1/ Due to conversion from English to metric units and to rounding, individual cell values may not agree with corresponding mileage table cell values. May see differences from prior years; starting in 1999, number of lanes is coded for all systems except rural minor collector and rural/urban local.

2/ Rural minor collector and rural/urban local functional system lane-kilometers estimated by FHWA assuming two as the number of lanes.

3/ Excludes 1,268 kilometers of Federal agency owned roads.

VM-2M: Functional System Travel Annual Vehicle-Kilometers

1/ Travel for the rural minor collector and rural/urban local functional systems is estimated by the States based on a model or other means and provided to the FHWA on a summary basis. Travel for all other systems are estimated from State-provided data in the Highway Performance Monitoring System. Due to conversion from English to metric units and to rounding, individual cell values may not agree with corresponding vehicles-miles table cell values.

2/ Excludes 1,268 kilometers of Federal agency owned roads.

3/ State has revised their adjusted urbanized area boundaries and/or functional classifications.

VM-3M: Federal-Aid Highway Travel Annual Vehicle-Kilometers

1/ Travel for the rural minor collector and rural/urban local functional systems is estimated by the States based on a model or other means and provided to the FHWA on a summary basis. Travel for all other systems are estimated from State-provided data in the Highway Performance Monitoring System. Due to conversion from English to metric units and to rounding, individual cell values may not agree with corresponding vehicle-miles table cell values.

2/ Excludes 1,268 kilometers of Federal agency owned roads.

3/ State has revised their adjusted urbanized area boundaries and/or functional classifications.

 
 
Updated: 01/03/2012
 

FHWA
United States Department of Transportation - Federal Highway Administration