Route Number Designations

U. S. Route Designations

Establishment and Development of United States Numbered Highways

(Retained from October 13, 1991, Revised October 6, 1996) HO1
Copied from the AASHTO Transportation Policy Book, January, 1998 Edition

The purpose of the U.S. road numbering and marking system is to facilitate travel on the main interstate lines, over the shortest routes and the best roads. To serve that purpose a system of main interstate routes was designated, and a uniform system of guide and warning signs was adopted for use in all the State, on such designated routes. This system was established in 1926. It has passed the preliminary development state. It has reached the period of review, revision, and consolidation. The U.S. road system now needs perfecting rather than expansion.

New construction has opened up newer, better and shorter routes. Demands of interstate traffic have increased and are more exacting. Public acceptance of the U.S. numbered system has made possible the rectification of early concessions made for the purpose of getting the system established and marked.

In harmony with the improved condition of State roads, the State route markers of the several States have more and more become a dependable trade mark of quality in those routes.

The establishment of a U.S. number as a guide for interstate travel over certain roads has no connection with Federal control or the designation of Federal funds for road construction. These numbers may recognize a State road which has been constructed entirely by the use of State funds.

Often the U.S. marker is interpreted by the public as identifying a “Federal Highway” whereas the routes making up the U.S. numbered system are under State jurisdiction and not under Federal jurisdiction.

It was never intended that the U.S. numbered system should absorb or supplant the State numbered routes. It is intended by uniform marking of a U.S. route in two or more States to facilitate the movement of Interstate traffic. Thus, with a relatively limited mileage, the U.S. numbered road system must meet the changing conditions if it is to endure and serve the purpose for which it was intended.

The routes comprising the National System of Interstate and Defense Highways will be marked with is own distinctive route marker shield and will have a numbering system that is separate and apart from the U.S. numbered system. The Interstate system marking and numbering is not to replace that of the U.S. system but is, in reality, a separate system of a limited mileage of modern expressways to accommodate major streams of traffic between the Nation’s major traffic generating areas; and the two numbered systems will complement each other. A large extent of the Interstate system is developed on new location. Those section where the Interstate system is developed over an existing U.S. numbered route, both the U.S. and the Interstate system shields and route numbers shall be used to mark those sections which are coincident. Otherwise, it is assumed that in the majority of instances the U.S. markers and numbers will remain on the routes as now established or as determined by subsequent Standing Committee on Highways action, as new construction makes available new and better routes.

Special Route Definitions

In connection with the U.S. numbering plan, as evolved and perfected, it has been found necessary and expedient to recognize and establish “Business Routes,” “By-Pass,” “Alternate Routes,” and “Temporary Routes,” which have been defined as follows:

Business Route: A “Business Route” is a route principally within the corporate limits of a city which provides the traveling public an opportunity to travel through that city, passing through the business part of the city, while the regular number is used to obviate passing through the congested part of the city. This “Business Route” connects with the regular numbered route at the opposite side of the city limits.

“Business Route” numbering shall be established by the placing of a standard strip carrying the words “Business Route” on the staff above the U.S. shield.

By-Pass: A “By-Pass Route” or a “Relief Route” is a route which is established for the purpose of designating a route which entirely by-passes a city or congested area and joins in with the regular numbered route beyond the city or congested area. This enables the regular number to be carried both through the city and around the city without either designation carrying any other sign or lettering showing a preference.

The “By-Pass Route” or “Relief Route” shall be designated by the erection of a standard strip on the staff carrying the U.S. shield, on which are the words “By-Pass” or “Relief Route,” as local preference may dictate.

Alternate Route: An “Alternate Route” shall be considered a route which starts at a point where it branches off from the main numbered route, may pass through certain cities and towns, and then connect back with the regular route some miles distant. Since it is the purpose of the U.S. numbered system to mark the best and shortest route available, an alternate route should be designated only where both routes are needed to accommodate the traffic demand and when the alternated route has substantially the same geometric and structural design standards of the main marked routing.

It is recommended that, in cases where an alternate route is marked, the shorter and better constructed route be given the regular number and the other section designated as the “Alternate Route.” It is further recommended that the Highway Department erect signs at the junction points of the regular and alternate routes giving the distance between the cities or points concerned.

The State Highway Departments involved in the establishment of “Alternate” routes shall adopt the same procedure with the Standing Committee on Highways of the Association as applies to the creation of a new route.

The “ Alternate Route” shall be marked by the erection of signs bearing the same U.S. number as the regular route and above the shield shall carry a standard strip with the words “Alternate Route.”

In no instance should an alternate routing be used for the purpose of keeping an obsolete section on the U.S. numbered system after a new routing has been constructed and available to traffic.

Temporary Route: In the erection of signs for numbering routes, it is necessary in some cases to carry a number temporarily over a road that ultimately will not be the permanent location of that number. Great care should be taken by the State Highway Departments in seeing that, when numbers of this character are permitted, a standard strip carrying the words “Temporary Route” shall be placed on the staff above the number. This will obviate much hard feeling when it is necessary to change a number to the permanently established route.

The word “Temporary” on a standard strip above the regular U.S. numbered shield should also be used where it is necessary to establish a detour.

Established Policies

1. The Standing Committee on Highways of the American Association of State Highway and Transportation Officials shall have full authority to review the U.S. numbered road system and the numbering and marking thereof, to make addition, changes, extensions, revisions or reductions in said road system and to revise the numbering or marking thereof.

2. Before approving any addition, change, extension, revision or reduction in the U.S. numbered road system or the numbering or marking of any U.S. numbered road, the Standing Committee on Highways shall consult the State Highway Department of the State or States through or within which such addition, change, extension, revision or reduction is located.

3. The State Highway Department, by a favorable vote on the adoption of this program and policy, agrees and pledges its good faith that it will not erect U.S. markers on any road or take down or change the U.S. markers on any road without the authorization, consent or approval of the Standing Committee on Highways of the American Association of State Highway and Transportation Officials, notwithstanding the fact that the changes proposed are entirely within that State.

4. No additional road shall be added to the U.S. numbered road system, and no existing U.S. road shall be extended except where there is a definite showing of an adequately improved highway carrying an established and necessary line of interstate traffic not otherwise provided for by existing U.S. routes and for which traffic adequate service cannot be provided by State route numbers.

Extension of present U.S. numbered routes may be made only when the proposed extension is in the general direction of the present route.

Proposed extensions shall not be made when, to do so, it is necessary to duplicate U.S. routes already established, unless the duplication is for a short distance and the routes then diverge, ending in different terminal points.

5. No new U.S. route located wholly in one State shall be established. U.S. routes, less than three hundred miles in length, heretofore established and located wholly in one State, shall be eliminated either by consolidation with other U.S. routes or by reverting to State routes, as rapidly as the State Highway Department and the Standing Committee on Highways of the American Association of State Highway and Transportation Officials can reach agreement with reference thereto.

6. The Standing Committee on Highways shall encourage the State Highway Departments in the development of continuous State route numbers extending into two or more States rather than the establishment of additional U.S. numbered routes, and shall encourage the substitution of continuously numbered State routes for relatively short U.S. routes now located in two or more States.

7. No new divided numbered (such as U.S. 96W and U.S. 96E, etc.) shall be adopted. Existing divided U.S. numbers shall be eliminated as rapidly as the State Highway Department and the Standing Committee on Highways can reach agreement with reference thereto.

8. Existing U.S. routes shall be consolidated, improved and shortened:

(a) By connecting two or more relatively short routes into one longer route,

(b) By relocating portions of existing routes so as to follow newer, better or shorter roads,

(c) By establishment of new numbers following, in general, existing U.S. numbered routes but taking advantage of new roads or short cuts where the changing of present numbers is not practical

9. A suitable highway legend, which may be copyrighted, shall be adopted by the Standing Committee on Highways on behalf of AASHTO. Such legend will be recommended for use to all travel map makers, also for use by the State Highway Departments. This legend is to show, in a uniform manner, the suitability for travel not only of the U.S. numbered routes but also of State routes.

10. Any proposal that would exploit the prestige of the U.S. numbered highway system to direct traffic over routes that are not the shortest and best available between major control points on the system, especially when it appears to be for the purpose of benefiting businesses located along such a proposed routes, shall constitute reason for denying any application to make such an addition to the system.

11. Since the U.S. numbered system was established by joint action of the State Highway Departments, only those applications for changes in or additions to the U.S. numbered system from the Member State Highway Department involved shall be considered by the Standing Committee on Highways. Those local officials, organizations, groups, or individuals interested in a change or in an addition to the system should contact their State Highway Department and not the Standing Committee on Highways. The Standing Committee on Highways shall consider only those applications from State Highway Departments that are filed on the official form and are complete in all detail to the degree that the Standing Committee on Highways can evaluate the need for the adequacy of the proposed route from the application form submitted and without a representative of the State Highway Department appearing before the Committee to supply additional information.

12. No person or group of persons shall be allowed to appear either before the Standing Committee on Highways or its Special Committee on U.S. Route Numbering except in the case of a State Highway Department requesting reconsideration of an action by the Standing Committee on Highways in regard to an application filed by that Department.

13. In case a proposed change in or addition to the U.S. numbered system involves two or mores States, the proposal shall be given official consideration only when all affected State Highway Departments have filed applications to cover the complete proposal. In the case of a multistate proposal regarding the Interstate System when one or more of the States involved declines to file an application, AASHTO shall refer the proposal to the Federal Highway Administration without recommendation.

14. No route should be considered for inclusion in the U.S. numbered system that does not substantially meet the current AASHTO design standards.

15. Any toll highway facility may be included in the U.S. Numbered System when it meets all the criteria for inclusion, and when the request for the marking originates with the official authority having jurisdiction over the toll facility and the request is directed to AASHTO and supported by the appropriate Member Department. The word “Toll” shall appear over the official U.S. Route Marker and a toll-free routing between the same termini shall continue to be retained and marked as part of the U.S. Numbered System.

16. Notwithstanding established policies, AASHTO recognizes that Congress on occasion will establish highway routes, specifying the location for the route as well as designating the route number(s) to be used. In those instances when Congress designates a route, the state(s) affected will follow the established procedures relative to route numbering.

These purposes and polices, having been amended and approved by the State Highway Departments after individual State consideration, the Standing Committee on Highways of the American Association of State Highway and Transportation Officials hereby promulgates and makes effective these policies upon the authority of the State Highway Departments beginning September 15, 1970.

It is realized that this work is a continuing obligation and that even reforms made evident from past experiences cannot be accomplished at once. It is the judgment of those to whom this obligation has been delegated that all far-seeing citizens will aid the State Highway Departments in their efforts to make this numbering system of the greatest use to the traveling public.

In this connection it should be noted that, while additional routes for U.S. numbering will be greatly limited, stress will be laid upon the availability of many State numbered routes for interstate travel. Map makers will be urged to recognize U.S. numbered roads and well-established State numbered roads as of equal importance-both to be printed in the same color.

Establishment of a Marking System of the Routes Comprising the National System of Interstate and Defense Highways

(Retained from August 10, 1973) HO2

The National System of Interstate and Defense Highways known as the “Interstate System” will be a part of the State Highway systems of the several States and the District of Columbia and will therefore be maintained, operated and policed by those jurisdictions. It therefore becomes the responsibility of the several states to mark and number the System.

Since these highways join centers of population and defense establishments and join with the major international highways at the Mexican and Canadian borders, they constitute a nationwide network of the most important highways; therefore, for the convenience of the motorist, there must be continuity and a uniform pattern of marking and numbering these routes without regard to State lines.

In arriving at a route marking and numbering policy the following guides shall be used by the Association:

The Standing Committee on Highways shall determine and assign the numbers to be used in marking the routes of the Interstate System;

No new divided numbers (such as I-35W and I-35E, etc.) shall be adopted. Existing divided Interstate
numbers shall be eliminated as rapidly as the State Highway Department and the Standing Committee on Highways can reach agreement with reference thereto;

3. That there will be no Interstate Route bearing the same number designation as a U.S. Numbered Route in any State;

4. That sufficient room be left in assigning numbers to the routes of the Interstate System to allow for future expansion of the system and keep the numbering pattern in sequence;

5. That no area has any vested right to any route number;

6. That the routes be so marked as to give maximum continuity between major control points and that dual Interstate numbering be held to a minimum consistent with proper travel guidance;

7. That U.S. Route numbers may be used in conjunction with Interstate Route markers where the U.S. Route leads into the Interstate Route, follows it for a reasonable distance, and then departs again from the
Interstate Route;

8. The Interstate Highway patterns in urban areas be carefully numbered and marked for the safety and
convenience of the traveling public and, to insure uniformity of practice, that each State Highway
Department is to submit its plan of numbering and marking of such urban areas to the Standing
Committee on Highways for approval prior to the erection of markers; and

9.That a distinctive, easily recognized route marker-shape, color and sizes-be adopted and universally used.

Purpose and Policy, U.S. Numbered Bicycle Routes

(Retained from June 30, 1982) HO3

Purpose

The purpose of the U.S. bicycle route numbering and marking system is to facilitate travel between the states over routes which have been identified as being more suitable than others for cycling.

Definition

A bicycle route is any road, street, path or way which in some manner is specifically designated as being open to bicycle travel, regardless of whether such facilities are designated for the exclusive use of bicycles or are to be shared with other transportation modes.

Policies

1. The Standing Committee on Highways of the American Association of State Highway and Transportation Officials shall have full authority to review the U.S. numbered bicycle route system and the numbering and marking thereof, to make additions, changes, extensions, revisions or reductions in said route system and to revise the numbering or marking thereof.

2. Before approving any addition, change, extension, revision or reduction in the U.S. number bicycle route system, or the numbering or marking of any U.S. numbered bicycle route, the Standing Committee on Highways shall consult the State Highway or Transportation Department of the State or States through or within which such addition, change, extension, revision or reduction is located.

3. The State Highway Department, by a favorable vote on the adoption of this purpose and policy, agrees and pledges its good faith that it will not erect U.S. markers on any route without the authorization, consent or approval of the Standing Committee on Highways of the American Association of the State Highway and Transportation Officials, notwithstanding the fact that the changes proposed are entirely within that State.

4. No U.S. numbered bicycle route shall be designated that does not extend between two or more States and is mapped and /or appropriately marked along its length.

5. The bicycle route marker included in the Manual on Uniform Traffic Control Devices is recommended for use to all travel map makers, also for use by the State Highway and Transportation Departments.

6. Any proposal that would exploit the prestige of the U.S. numbered bicycle route system, especially when it appears to be for the purpose of benefiting businesses located along such a proposed route, shall constitute reason for denying any application to make such an addition to the system.

7. Since the U.S. numbered system was established by joint action of the State Highway or Transportation Departments, only those applications for change in or addition to the U.S. numbered system from the Member State Highway or Transportation Department involved shall be considered by the Standing Committee on Highways. Those local officials, organizations, groups, or individuals interested in a change or in an addition to the system should contact their State Highway or Transportation Department and not the Standing Committee on Highways. The Standing Committee on Highways shall consider only those applications from State Highway or Transportation Departments that are filed on the official form and are complete in all detail to the degree that the Standing Committee on Highways can evaluate the need for an adequacy of the proposed route from the application form submitted and without a representative of the State Highway or Transportation Department appearing before the Committee to supply additional information.

8. No person or group of persons shall be allowed to appear either before the Standing Committee on Highways or its Special Committee on U.S. Route Numbering except in the case of a State Highway or Transportation Department requesting reconsideration of an action by the Executive Committee in regard to an application filed by that Department.

9. In case a proposed chance or addition to the U.S. numbered bicycle route system involves two or more States, the proposal shall be given official consideration only when all affected State Highway or Transportation Departments have filed applications to cover the complete proposal.

10. No route should be considered for inclusion in the U.S. numbered system that does not substantially meet the current AASHTO design standards contained in the AASHTO Guide for Development of New Bicycle Facilities

In the Establishment of a marking system of the Routes Comprising of the National System of Interstate and Defense Highways

State Route Designations

Route number assignments in general are made in a manner to guide the unfamiliar traveler to desired destinations. These assignments have developed into a network of routes that connect major centers of population, industry, and government. The basic criteria used to determine the need and location of routes are traffic demand, directness of the highway connections, highway conditions, length, and safety factors.

Traffic Demand - Compare traffic on proposed route to traffic on existing routes in the same area.

Highway Conditions - Compare pavement widths and shoulder widths on proposed route to conditions on existing routes in the same area.

Directness - Compare mileage and speed on proposed route to produce an estimate travel time. Compare travel time on proposed route to travel time on existing route in the same area.

Safety - Request and review accident summaries. Field review to look for hazards.

Other Items - Look at density of routes already present in the area. Look at present configuration of signs in the area.