Highways and Highway Transportation by George R. Chatburn

PLANNING HIGHWAY SYSTEMS: SELECTION OF ROAD TYPES 222 Object of a Road. Road Classification: Agricultural. Recreational, Commercial, Military. Problem of the Road Planner: Economy, Accommodation, Utilizing Existing Roads. Essentials to be Considered: Ruling Points, Branch Lines and Detours, Alternate Routes, Existing Highways and City Streets, Vested Rights, Widening Roads and Streets, Railroads, Trolley Lines, etc., Bridges, Culverts, Drainage, etc., Ruling Grades, Esthetics. Motor Transport Efficiency Outline, Highway System Unit: Arguments in Favor of National System -- Eliminates Sectional Differences, Gives Continuous Roads, Military Roads, Benefits of Example. State Systems -- Benefits. Procedure of Laying out a Road System: Commission, Determining Factors, Maps, Tentative System, Reconnaisance Survey -- What Shown, How Taken, Instruments; Hearings -- Object; Final Location -- Considerations, Traffic Census Advisable. Financial Considerations: First Cost, Upkeep, Traffic Census: Affects Location, Type of Road, Grades, Width, Foundations. Making a Traffic Census: Variation of Traffic -- Number of Counting Days, Hours Each Day, Weights, Observer’s Cards, Both Way Count, Weather, Stations -- Location of. Classification of Traffic: Object, Maximum Loads, Effect of Heavy Loads, Influence Units of Traffic -- British, French, Other Countries, Maryland, Massachusetts, Borough of Brooklyn; Suggested Form of Traffic Sheet -- New Jersey. Destructive Factors: Density of Traffic, Weight of Vehicles, Impact, Speed, Wrinkling, Sprung and Unsprung Weight, Tires, Pleasure Cars and Light Traffic to be Considered. Other Methods of Estimating the Amount of Traffic: Area Served, Tonnage Arising. Distribution of Traffic over Township Roads. Selection of a Suitable Type of Road. Taxpayers Allowed to Assist in Selection, Engineers to Suggest. Ideal Road: Qualities of -- Low First Cost, Durability -- Materials and Design, Resistance to Traction and Tractive Force -- Horse, Truck, Speed, Temperature, Roughness, Width of Tire, Diameter of Wheel, Table of Resistances; Resistance Due to Grade -- Formulas, Coefficient, Available Engine Effort; Slipperiness -- Type of Pavement, Climatic Conditions; Sanitariness -- Definition, Effect of Type of Road; Noisiness; Acceptability. Some Types of Roads and their Qualities: Earth, Sand-clay, Gravel, Macadam, Bituminous Macadam, Bituminous Concrete, Brick, Concrete, Creosoted Wood Block, Asphalt Block, Sheet Asphalt, Other Types. Comparison of Roads -- Specimen Tables.