ROAD DESIGN
Necessity for Planning—Road Plans—Problems of Design—Preliminary Investigations—Road Surveys—Alignment—Intersections—Superelevation—Tractive Resistance—Rolling Resistance—Internal Resistance—Air Resistance—Effect of Trades—Energy Loss on Account of Grades—Undulating Roads—Guard Railing—Width of Roadway—Cross Section—Control of Erosion—Private Entrances—Æsthetics
42-62
EARTH ROADS
Variations in Soils—Variation in Rainfall—Cross Sections Elevating Grader—Maney Grader—Slip Scraper—Fresno Scraper—Elevating Grader Work—Use of Blade Grader—Costs—Maintenance—Value of Earth Roads
63-73
SAND-CLAY AND GRAVEL ROADS
The Binder—Top-soil or Natural Mixtures—Sand-clay on Sandy Roads—Sand-clay on Clay or Loam—Characteristics—Natural Gravel—The Ideal Road Gravel—Permissible Size of Pebbles—Wearing Properties—Utilizing Natural Gravels—Thickness of Layer—Preparation of the Road—Trench Method—Surface Method—Maintenance