rily for students who do not
receive training along the lines of the usual course in Highway or
Civil Engineering.

The text is intended to familiarize the student with the relation of
highway improvement to national progress, to indicate the various
problems of highway administration and to set forth the usual methods
of design and construction for rural highways in sufficient detail to
establish a clear understanding of the distinguishing characteristics
and relative serviceability of each of the common types of roadway
surface.

Experience with classes made up of students in agriculture or
agricultural engineering and with trade school students in road making
served as a guide in the selection and arrangement of the material.
Detailed discussion of tests of materials and of the theory of design
has to a considerable extent been eliminated as being outside of the
scope of the course for which the text is intended.

In the preparation of American Rural Highways reference was had to
many books on highway subjects and to current periodical literature.
Wherever direct extracts were made from such source, appropriate
acknowledgment appears in the text.

T. R. AGG

AMES, IOWA,
AUGUST 18, 1920.

CONTENTS

PREFACE vii

CHAPTER I

THE PURPOSE AND UTILITY OF HIGHWAYS

Transportation Problem--National in Scope--Development in
Traffic--Location or Farm to Market Traffic--Farm to Farm
Traffic--Inter-City Traffic--Inter-County and Inter-State
Traffic--Rural Education--Rural Social Life--Good Roads and
Commerce 1-12

CHAPTER II

HIGHWAY ADMINISTRATION

Township Administration--County Administration--State
Administration--Federal Administration--Special Assessments--Zone
Method of Assessing--General Taxation--Vehicle Taxes--Sinking
Fund Bonds--Annuity Bonds--Serial Bonds--Comparison of Methods
of Issuing Bonds--Desirability of Road Bonds 13-28

CHAPTER III

DRAINAGE OF ROADS

The Necessity for Drainage--Importance of Design--Surface
Drainage--Run-off--Ordinary Design of Ditches--Underground
Water--Tile Drains--Lying Tile--Culverts--Length of Culvert--
Farm Entrance Culverts--Metal Pipe--Clay and Cement Concrete
Pipe--Concrete Pipe--Endwalls for Culverts--Reinforced Concrete
Box Culverts--Drop Inlet Culverts