Highway Engineering: History and Development

• Highway engineering deals with road system planning, route selection, construction, and maintenance.

Brief History of Roads

• Early hard surface roads date back to 3500 BC in Mesopotamia.
• Stone surface roads were similarly constructed in Crete and by the Mayans, Aztecs, and Incas in the Western Hemisphere.
• The Romans used cement to expand their empire with an extensive road network, many of which still exist after 2000 years.

Purpose of Early Road Systems

• Roads were used for military movement during conquest or defense.
• Roads facilitated the transportation of food and trade goods.

Key Figures in Road Development

• Jerome Tresaguet (1716-1796): Introduced new methods of construction and maintenance, improving the crown, drainage, grade, and stone foundation.
• Thomas Telford (1757-1834): Improved Tresaguet's methods, using a flat sub-grade with a slight crown and stones of varying sizes; also the founder of the Institute of Civil Engineers.
• John Louden Mac Adam (1755-1836): Developed the Macadam road building concept.
• Eli Blake: Invented the first stone crusher.
• Aveling and Porter: Invented the 30-ton road roller.

Highway Development in the Philippines

• In the early 1900s, transportation relied on trails, water routes, railroads, earth roads, and partially graveled roads.
• The American government initiated roadway system development, replacing mostly trails and earth roads from the Spanish era.
• After WWII, the Philippine government focused on road development using war reparations from Japan and financial aid from the U.S.

Modern Road Development

• The period from 1950 to the early 1980s was considered the automobile age, with road construction becoming a government priority.

Highway Programming Input Separations

• Economic: Deals with resource questions.
• Financial: Focuses on who pays, who spends, and how much.
• Political and Administration: Involves the decision-making process.
• Highway programming prioritizes economically viable projects that meet financial and political criteria.

Importance of Roads

• Provide convenience and rapid travel
• Help develop agriculture, commerce, and industries
• Aid in the development of natural resources
• Contribute to social life and general education
• Boost tourist travel
• Increase rural and suburban population
• Decrease transportation costs
• Increase land revenue
• Improve sanitary conditions
• Facilitate national defense movement

Vehicle and Vehicular Characteristics

• Roads should accommodate various vehicles, considering design standards and vehicular characteristics.

Important Vehicle Characteristics

• Width: Affects lane and shoulder width, as well as parking space dimensions.
  • Maximum width is important for design considerations.
• Length: Impacts pavement width, turning radius, road capacity, and parking facilities.
• Height: Affects clearance under structures and lateral stability on curves.
  • (a) Single-deck vehicle: 3.81 meters
  • (b) Double-deck vehicle: 4.27 meters
• Maximum dimensions:
  • Maximum width of truck bus: 2.44 meters
  • (a) Single unit with two axles: 10.67 meters
  • (b) Single unit with more than two axles: 12.19 meters
  • (c) Semi-trailer tractor combination: 15.24 meters
  • (d) Tractor and trailer combination: 18.29 meters
• Weight: Affects pavement thickness, longitudinal grades, and bridge design.
  • No axle load should exceed 8.165 tons.
  • Total load should not exceed w = 1525 (L + 7.3) – 14.70L2 kg.
  • Total load should not exceed 14515 kg when L is less than 2.44 meters.
• Vehicle Power: Influences gradient limits.
• Vehicle Speed: Affects geometric standards like super elevation, curve lengths, pavement width, and traffic control.
• Braking Characteristics: Relate to brake efficiency, stopping distance, and highway capacity.

Highway Plans and Specifications

• Plans and specifications provide instructions and conditions for highway and bridge construction.
• Plans include engineering drawings, while specifications provide written instructions and conditions.

Schemes for road geometric design

• Traffic
• Drainage
• Erosion Control
• Roadside Development
• Structure
• Soils
• Pavement

Subjects Covered by Standard Drawings

• Pipe Culverts
• Concrete Box Culverts
• Guard Rail and Parapet
• Curbs
• Gutters
• Curb Structures
• Sidewalks
• Drainage inlet and outlet
• Manholes
• Rip-rap and other devices for bank protection
• Fences and right-of-way
• Survey markers

Two Types of Highway Specifications

• Standard Specification: Applies to projects with recurring subjects, like agency work.
• Special Provisions: Covers specific project items and includes modifications to standard specifications, along with documents for competitive bids and contracts.