BULLETIN OF THE 
No. 220 
Contribution from the Office of Public Roads, Logan Waller Page, Director 
June 7, 1915. 
ROAD MODELS. 
Prepared by the Office of Public Roads. 
CONTENTS. 
Page. 
Introduction 1 
Roman roads 2 
French roads 3 
Macadam method of construction 5 
Telford method of road building 6 
Local ion and alignment 7 
Foundation, or subgrade, and shoulders 7 
Earth and sand-clay roads 10 
Gravel roads - - 12 
Page. 
Macadam roads 13 
Cement concrete roads 17 
Bituminous concrete roads— " Topeka speci- 
fication " 18 
Paved roads other than concrete 18 
Culverts and bridges 20 
Roadside treatment 21 
Road machinery 22 
INTRODUCTION. 
The Office of Public Roads of the United States Department of 
Agriculture made an exhibit of road models for the first time in 1909 
at the Alaska- Yukon-Pacific Exposition. The aim was to put on 
view such striking examples hi miniature of model roads that visitors 
would not only appreciate the beneficent effects of improved roads 
but would, at the same time, be able to understand the methods of 
their construction. 
Since the Alaska- Yukon-Pacific Exposition closed, the exhibit of 
the Office of Public Roads has been displayed at Omaha, Nebr., dur- 
ing the National Corn Exposition; at Knoxville, Tenn., during the 
Southern Appalachian Exposition; at Chicago, 111., during the 
National Land and Irrigation Exposition; at New York City during 
the Travel and Vacation Exposition and the Domestic Science Expo- 
sition; at Atlantic City, N. J., during the American Road Congress; 
at Lethbridge, Alberta, during the International Dry-Land Congress ; 
at Buenos Aires, Argentina, during the International Agricultural 
Exposition; at Turin, Italy, during the International Exposition; 
Note.— This bulletin contains illustrations and descriptions of the models in miniature of roads, bridges, 
and culverts and of road machinery exhibited by the Office of Public Roads at expositions and fairs and 
on railroads. Methods of construction are discussed. 
87538°— Bull. 220—15- 
