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Note: revised in 1989, this document was electronically scanned in April, 2000. The scanned image was processed through Optical Character Recognition software, the resulting text being formatted for the World Wide Web. Changes are restricted to:

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FHWA Functional Classification Guidelines

CONTENTS

Original page numbers are retained, providing easy reference back to the original document in hardcopy form. They also provide a convenient location on the page from which to link to another electronic page.
Section
 Original Hard Copy Page #
/links to electronic pages
I Introduction I -1
II Concepts, Definitions, and System Characteristics II -1
The Concept of Functional Classification II -1
Area Definitions II -5
Functional System Characteristics II -8
Functional systems for rural areas II -8
Functional systems in urbanized areas II -11
Functional systems for small urban areas II -14
Special urban-rural identification II -15
Classification criteria for Alaska, Hawaii and Puerto Rico II -15
III Suggested Procedures for Rural, Small Urban Aarea and Urbanized Area Classification III -1
Introduction III -1
Classification Procedures for Rural Systems III -3
Identifying and ranking population centers and other travel generators III -3
Classification of rural systems III -6
Classification Procedures for Small Urban Areas III -14
Determine and map the urban area boundary III -15
Prepare road network map III -15
Identify and map land service characteristics III -15
Classify the highway and street network III -15
Classification Procedures for Urbanized Areas III -18
Determine and map the urbanized area boundary III -18
Map the road network III -19
Perform a preliminary classification of the total arterial system III -19
Classify the final arterial system III -28
Classify the principal and minor arterial street systems III -28
Substratify the principal arterial system III -32
Classify collector and local streets III -34


Highway Functional Classification System

Concepts, Criteria and Procedures

SECTION I - INTRODUCTION

This reference manual includes sections on (1) concepts of functional highway classification and functional system characteristics and (2) suggested procedures for functional highway classification in rural, small urban and urbanized areas. The material herein is adapted from two previous FHWA manuals concerned with functional highway classification. The relationship of this manual to these previous documents is discussed below.

Two nationwide studies of functional highway classification were conducted during the period 1969-1971. The first of these, using criteria and procedures specified in the 1968 National Highway Functional Classification Study Manual, called for the functional classification of existing (1968) highways. The second study was carried out in accordance with procedures specified in the National Highway- Functional Classification and Needs Study Manual (1970 to 1990) . This latter study used the same functional classes and basic functional criteria as the first study, but provided for the classification to be based on projected 1990 facilities and usage.

The Federal-Aid Highway Act of 1973 required the use of functional highway classification to update and modify the Federal-aid highway systems by July 1, 1976. This legislative requirement is still effective today. Also a number of States have adapted the functional classes and criteria from these studies for their own purposes. For both these reasons, a need has developed for a republication of the functional classification concepts and criteria that were expressed in the aforementioned manuals, without the reference to specific study requirements that pertained in those manuals.

The functional classes and their characteristics defined in this manual are, for the most part, identical to those in the predecessor manuals. Text has been reworded only to the extent necessary for consistency and clarity and to delete reference to the original studies. The discussion of functional classification concepts is taken intact from the earlier of the two manuals.

Also included herein is a discussion of suggested classification procedures for rural, small urban and urbanized areas, which derives from the predecessor manuals, relying largely, in fact, on their original wording. This approach therefore provides first, a description of suggested procedures for classifying an existing network, followed by procedural suggestions for developing an updated or "future year" classification.

Procedures for functional classification in urbanized areas should be developed within the framework of the continuing, comprehensive, and cooperative planning process carried out pursuant to Section 134 of Title 23, U.S. Code.


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