Tiêu chuẩn quốc tế

• Số hiệu / Standard Number: AASHTO US:1989
• Năm ban hành / Publication date: 1989
• Tình trạng / Status: A - Còn hiệu lực
• Tên tiếng Anh / Title in English: United States Numbered Highways
• Số trang / Page: 220

Phạm vi áp dụng / Scope of standard

INTRODUCTION

In order to bring some order out of route designation over the
Nation, the American Association of State Highway Officials (AASHO)
in the early 20's requested the Secretary of Agriculture, under
whose offices the Bureau of Public Roads at that time operated, to
name a Committee for the purpose of formulating a plan or system of
numbered highways, principally for the assistance of motorists
engaged in Interstate travel. Subsequent to that action, this
Association was asked by the Secretary of Agriculture to develop
such a system.

After much study and deliberation, the system was developed and
officially adopted in 1926, and the administration and maintenance
of records is kept in the offices of the American Association of
State Highway and Transportation Officials, as AASHO is now
called.

For the benefit of those reading this book who are not familiar
with the organization of the AASHTO, it is made up of the 50 State
Highway and Transportation Departments, the District of Columbia
and Puerto Rico. In addition, a number of public highway and
transportation agencies in other nations belong to the Association
as affiliate members, and a number of substate transportation
agencies in the United States belong as associate members. This
system, as it was initially laid out for all practical purposes, is
still in effect. It is administered by the Executive Committee of
this Association. It is all a cooperative effort, and stands as a
monument to the several states in their adh-ence to the Purpose and
Policy, as adopted by the Association, and revised in September
1970. Following this introduction in this book there appears this
Purpose and Policy.

Between the 1955 and 1969 editions, the Executive Committee
approved changes in the system. As a result, the total mileage over
all U.S. Numbered Routes in 1969 was 167,231 miles. In 1955, this
was 169,760. In 1974 it had been reduced to 163,198. it was further
reduced in 1979 to 159,645. The mileage as of this book is 157,724
miles.

It is of interest to note that beginning in 1955, the Executive
Committee, which is the governing body of the AASHTO, approved the
use of a standard form for the purpose of submission of petitions
in the matter of requesting changes in the given state. In view of
the fact that the system, as now established, does not need
extension but rather improvement, the new form has been prepared
with the idea of giving the maximum amount of information as to the
traffic need and the road conditions to the Committee in order to
better serve them in their deliberations.

Specific attention is requested to the matter of supplemental
routes. In the instance of alternate routes, the parent route is
broken at the point of beginning of the alternate route, and the
alternate route is inserted in the log. At the conclusion of the
alternate route, the parent route continues from the point the
alternate route started and mention is made under the remarks
column at the point the alternate route rejoins.

Mileage on the alternate, by-pass and business routes starts
from zero. In the case of divided routes, such as North and South,
or East and West, the accumulated mileage from point of beginning
of the route is based on the North Section or the West section.
This information is noted on each route where it applies.