Highway Statistics 2004 - FHWA

Roadway Extent, Characteristics and Performance Section/International and Metric Tables Section FOOTNOTES of Highway Statistics 2002

Section VI: Metric Tables

Table number footnotes guide.

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.

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.
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.

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.

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.
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.

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.

HM-30M: 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.

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.
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.

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.

VM-2M: Functional System Travel Annual Vehicle-Kilometers (VKT)

1/ Travel for all systems are FHWA estimates based on State provided HPMS data. Due to conversion from English to metric units and to rounding, individual cell values may not agree with corresponding vehicles-miles table cell values.

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

1/ Travel for all systems are FHWA estimates based on State provided HPMS data. Due to conversion from English to metric units and to rounding, individual cell values may not agree with corresponding vehicle-miles table cell values.

If you have specific questions regarding Mileage and Travel, email us or phone (202) 366-0160.

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