Design--Properties of the Stone--Kinds of Rocks used for Macadam--Sizes of Stone--Earth Work--Foundation for the Macadam--Telford Foundation--Placing the Broken Stone-- Rolling--Spreading Screenings--Bituminous Surfaces--Maintenance Characteristics 89-97 CHAPTER VIII CEMENT CONCRETE ROADS Destructive Agencies--Design--Concrete Materials--Fine Aggregate--Proportions--Measuring Materials--Preparation of the Earth Foundation--Placing Concrete for Two-course Road--Curing the Concrete--Expansion Joints--Reinforcing--Bituminous Coatings on Concrete Surfaces--Characteristics--Maintenance 98-105 CHAPTER IX VITRIFIED BRICK ROADS Vitrified Brick--Paving Brick--Repressed Brick--Vitrified Fiber Brick--Wire-cut-lug Brick--Tests for Quality--Other Tests-- Foundation--Sand Bedding Course--Sand Mortar Bedding Course-- Green Concrete Bedding Course--Bituminous Fillers--Mastic Fillers--Marginal Curb 106-115 CHAPTER X BITUMINOUS ROAD MATERIALS AND THEIR USE Classes of Bituminous Materials--Coal Tar--Water Gas Tar--Natural Asphalt--Petroleum Asphalt--Mixtures--Classification According to Consistency--Road Oils--Liquid Asphalts--Asphalt Cements-- Fillers--Bitumen--Specifications--Surface Treatments--Applying the Bituminous Binder--Finishing the Surface--Patching-- Penetration Macadam--Foundation--Upper or Wearing Course-- Patching Characteristics--Hot Mixed Macadam--Foundation--Sizes of Stone--Mixing the Wearing Stone--Placing and Wearing Surface--Seal Coat--Characteristics--Asphaltic Concrete-- Bitulithic or Warrenite--Topeka Asphaltic Concrete--Foundation --Placing the Surface--Characteristics 116-129 CHAPTER XI MAINTENANCE OF HIGHWAYS Petrol Maintenance--Gang Maintenance--Maintenance of Earth, Sand-clay, Gravel and Macadam Roads 130-134 Index 135 AMERICAN RURAL HIGHWAYS CHAPTER I THE PURPOSE AND UTILITY OF HIGHWAYS THE DEVELOPMENT OF HIGHWAY SYSTEMS =Transportation Problem.=--Public highways, like many other familiar things, are utilized constantly with little thought of how indispensable they are to the conduct of the business of a nation or of the intimate relation they bear to the everyday life of any community. The degree to which a nation or a community perfects its transportation facilities is an index of its industrial progress and public highways constitute an important element in the national transportation system. It is to be expected that the average citizen will think of the public highway only when it affects his own activities and that he will concern himself but little with the broad problem of highway improvement unless it be brought forcibly to his attention through taxation or by publicity connected with the advancement of specific projects.