This section contains data on the physical, operational, usage, extent, and performance characteristics of public roads existing in the United States as of December 31,1995. Most of the historical information provides trends back to 1980, but some tables include data as far back as 1900.
The current data (1980 and forward) are based on the Highway Performance Monitoring System (HPMS). The HPMS comprises a combination of sample data on the condition, use, performance and physical characteristics of facilities functionally classified as arterials and collectors (except the rural minor collector system starting in 1993); certain additional condition and use data for all rural arterials and urban principal arterials; and system-type data for all public road and street facilities within each State. These data are reported by the States on an annual basis. In some years some States have failed to provide complete data. Footnotes have been included where appropriate to explain where data have been estimated from other available data.
Prior to 1980, other methods plus special national studies were used to obtain road and street information from the States.
ORGANIZATION OF TABLES
All of the tables in this publication are national summaries. State breakdowns of the same data (often more detailed) are available electronically via the FHWA web site, back to 1980 for most tables.
Almost all tables in this section contain rural and urban breakouts where urban indicates a population of 5,000 or more. Small urban areas contain 5,000 to 49,999 persons while an urbanized area is an area with 50,000 or more persons that encompasses the land area delineated by the Bureau of the Census at a minimum. The Bureau of the Census establishes urbanized area boundaries based on the density of the population (1,000 persons per square mile). The adjusted Census urbanized area boundary reflected in this publication is usually enlarged to include such additional areas as airports, satellite cities/towns, strip development adjacent to high-use roadways, and other areas and facilities that are important to or serve the urbanized area. In some cases, the adjusted urbanized area includes land that will become urban in some predetermined amount of time (such as 3-5 years). These boundaries are decided upon by State and local officials with the approval of the FHWA and are the ones upon which the urban notation in this publication is based.
Prior to 1980, the urban portion of the tables generally contains mileage and travel reported as being municipal.
Within the two major breakouts--Highway Mileage and Highway Usage and Performance--the tables in this section have been organized into four general data areas:
1. Public Road and Street Mileage - tables HM-210, HM-212, HM-214, HM-215, HM-220 and HM-251.
2. Travel - tables VM-201, VM-201A, VM-202 , and VM-203.
3. Motor Vehicle Crashes - tables FI-200, FI-210, FI-211, FI-220 and FI-221.
4. U.S. Territories - table R-200.
PUBLIC ROAD AND STREET MILEAGE
For the most recent years (1980 forward), all mileage tables in this publication include only "public road" mileage (23 United States Code 101) meaning any road or street under the jurisdiction of and maintained by a public authority and open to public travel. Table HM-210 contains the total public road mileage of roads and streets in the United States, classified by jurisdiction. Table HM-212 contains mileage by type of surface as does HM-251 with further breakdowns by functional system. Table HM-214 contains Federal-aid mileage classified by jurisdiction. Table HM-215 contains mileage of Federal-aid highways and is in the same format as its companion travel table, VM-203. Table HM-220 contains all public road mileage by functional system. This table is in the same format as table VM-202 and contains the mileage that corresponds to the travel contained in that table.
Prior to 1980 the mileage tables include some nonpublic and/or not-open-to-traffic roadways. In 1979, this accounted for about 95,000 miles, nationwide.
In the more recent years, the annual increases in total road and street mileage by construction are relatively small. Most construction is for the improvement of existing highways and streets, such as resurfacing those previously surfaced, widening facilities, reducing grades, minimizing curves, eliminating grade crossings, and other improvements that provide safer, more efficient public roads having greater traffic and load-bearing capacities. Most new mileage falls in the local functional system category that serves residential or business uses. Decreases in public road mileage do occur. In recent years, this has been due to the removal of some timber, forest access, and natural resource roads from general public use.
Roads in Federal forests and reservations may be part of the State and local jurisdictional systems and are included with the mileages reported for those systems. Mileage directly under Federal control is identified in tables HM-210 and HM-214.
The surface classifications used in the national summary tables, HM-212 and HM-251 identify only the visible surface types on existing streets and roadways. Many highways, either by original design or because of reconstruction, consists of more than one major type of construction material. No data relative to vertical composition are presented, except for the composite pavement type (starting in 1988) on the electronically available State tables where the reporting agency has indicated that a concrete roadway has been overlaid with one or more inches of compacted bituminous material.
Federal-aid Highway Mileage
Except for minor amounts of Federal highway mileage under the U.S. Forest Service, Bureau of Land Management, Bureau of Indian Affairs, National Park Service, Fish and Wildlife Service, and the military, practically all of the roads and streets in the United States are under the jurisdiction of State and local governments. The Federal-aid highways are, basically, segments of State and local system mileage eligible for Federal aid. Except under special circumstances, this excludes roads that are functionally classified as rural minor collector or rural and urban local.
The designation of a road or street as a Federal-aid highway does not alter its ownership or jurisdiction as a State or county road or city street. A Federal-aid highway simply means that, because of its service value and importance, it has been made eligible for Federal-aid construction and rehabilitation funds.
The Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991 eliminated the historical Federal-aid Systems and created the National Highway System (NHS) and other Federal-aid highway categories. The National Highway System Designation Act of 1995 approved the NHS established under ISTEA. (For purposes of this publication, the NHS excludes any nonroadway routes, i.e., ferry boat routes.) Highways designated as parts of the Interstate System are included in the NHS.
All historical tables linked to the superseded Federal-aid Systems have been changed to reflect the NHS and other Federal-aid highways, as applicable. The changes are particularly evident in the Federal-aid tables starting in 1992. These include tables HM-214, HM-215, VM-203, and portions of the FI series.
The Eisenhower National System of Interstate and Defense Highways was originally established by the Federal-Aid Highway Act of 1944. The Federal-Aid Highway Act of 1956 and the companion Highway Revenue Act of 1956 further defined the purpose and extent of the system and, as subsequently amended, dedicated a group of Federal excise taxes on motor fuel and automotive products to the support of Federal-aid highway activities. By law, the Interstate System is limited to 42,500 miles under Section 103 of Title 23 and other routes incorporated under Section 139(a) of Title 23 that are logical additions or connections and meet Interstate System design standards. The Interstate System under Section 139(c) is limited only to Alaska and Puerto Rico. Highways may also be designated as part of the Interstate System under provisions of Section 1105(e) of ISTEA as amended under Section 332 of the National Highway System Designation Act of 1995.
The Interstate System in conjunction with the rest of the National Highway System connects, as directly as practicable, the Nation's principal metropolitan areas, cities, transit facilities and industrial centers; serves the national defense; and connects at suitable border points with routes of continental importance.
FUNCTIONAL SYSTEM MILEAGE
The functional systems result from the assignment of streets and highways into groups according to the character of service they are intended to provide. Because most travel involves movement through a network of roads, individual roads and streets do not serve travel independently in any major way. Functional classification defines the role that a particular road or street plays in serving the flow of trips through a highway network. The functional systems are: (1) arterial highways, which generally handle the long trips, (2) collector facilities, which collect and disperse traffic between the arterials and the lower level, and (3) local roads and streets, which serve the land access function to the residential areas, businesses, individual farms and ranches, and other local areas. The functional system data are identified in tables HM-212 (electronic versions only), HM-220, HM-251, VM-202, FI-220 and FI-221.
Because the principal arterial functional classifications for both rural and urban include a separate category for Interstate, the Interstate functional classification is the only stratification where there is direct correspondence with a Federal-aid system category. Interstate mileage, travel and crash information have been included in both the Federal-aid and functional system tables. Although this is a duplication, it is necessary to provide complete summaries of both system types.
Table VM-201 contains estimates of annual vehicle distance traveled in miles by vehicle type and highway category. Beginning in 1966, separate totals are shown for urban and rural Interstate highways. Table VM-201A contains totals related to vehicle registrations and fuel use.
Table VM-202 contains a summary of the States' estimated highway travel based on traffic counts taken along selected highway sections which are grouped into functional systems, according to the character of service they provide. It is a companion to table HM-220.
Table VM-203 contains the estimated highway travel carried by Federal-aid highways. It is a direct companion to the mileage table HM-215 starting in 1980. Prior to 1980, table VM-203 reflects actual Interstate roadways that were open to public travel rather than the traveled way portrayed in the mileage table, HM-215; other Federal-aid systems are more directly relatable.
MOTOR VEHICLE CRASHES
The FI series contains the total persons fatally and nonfatally injured in motor vehicle crashes on the Nation's highways. Table FI-200 contains total public road mileage, estimated annual vehicle-miles of travel, total persons fatally injured
plus annual rates for mileage, travel, registered vehicles and licensed drivers. Tables FI-210 and FI-220 contain total persons fatally injured on Federal-aid highways and on the functional systems, respectively; these tables are in the same format as the travel tables VM-203 and VM-202, respectively, and the mileage tables HM-215 and HM-220, respectively. Tables FI-211 and FI-221 contain total persons nonfatally injured on Federal-aid highways and on the functional systems, respectively; these tables are also in the same format as the travel and mileage tables noted above.
Starting in 1976 fatality data are based on the 30-day definition; a fatality resulting from a highway vehicular crash is to be counted only if death occurs within 30 days of the crash. Prior to 1976, fatality data included persons counted under State rules that varied from within 30 days to as long as one or two years after the crash.
Table R-200 contains information for the U.S. territories including the Caribbean areas of Puerto Rico and the Virgin Islands, and the Pacific areas of American Samoa, Guam and the Northern Mariana Islands. The information for each area includes motor vehicle registrations, motor fuel consumption, resident population, licensed drivers, public road mileage, highway vehicular travel and persons fatally and nonfatally injured in highway vehicular crashes. The tables are based on data provided by the territories and although there are many missing entries, it is the most comprehensive summary of such information available.