Highway Engineering and Ancient Roads

Highway Engineering

• Is a branch of civil engineering that involves the planning, design, construction, operation, and maintenance of roads, bridges, and tunnels.
• Highway engineering became important after World War II in the latter half of the 20th Century.
• Highway engineers design roads with safe and efficient transportation of people and goods in mind.
• Standards of highway engineering continually improve.
• Must consider future traffic flows, geometric alignment, highway pavement materials, structural design of pavement thickness, and pavement maintenance.

Ancient Roads

• Roads predate recorded history, in the form of trackways and human pathways.
• Roads became essential for civilizations and empires.
• Roman roads were built on a massive scale, radiating outwards, providing military advantage.
• Roman Roads have lasted for over 2000 years.
• The earliest documented road was built near the Assyrian empire around 1900 BC.

Roman Roads

• Romans built extensive road systems across Europe, Asia Minor, and North Africa.
• Romans focused on drainage, materials, and workmanship.
• The main features of Roman roads included straight paths regardless of gradient and heavy foundation stones.
• Romans used concrete, created by mixing lime, volcanic puzzolana, and gravel, a major innovation for road building.
• Road sections were on average 750-1200 mm thick.

Roman Road Construction

• Features included:
  • Kerbstone
  • Lime concrete
  • Broken stones in lime concrete
  • Large stone slabs (10-15 cm thick)
  • Subgrade (10-20 cm thick)
  • Large foundation stones in lime mortar
  • Typical road width (5.5-6 meters)
  • Drain
  • Compacted slabs of crushed stone in cement
  • Dressed stone in cement
  • Stone blocks
  • Stone ditch

French Roads or Tresaguet Road

• The next major development in road construction occurred during Napoleon.
• Tresaguet made significant contributions in 1764, developing a more economical method compared to the Roman attempts.
• The pavement Tresaguet developed utilized 200 mm pieces of quarried stone, compacted with smaller broken stones to create a level surface.

Telford Construction

• Scottish engineer, Thomas Telford, developed a method using a 9-meter width foundation.
• Large, 40-mm wide, 170-220-mm deep stones were laid.
• Spaces between these were filled, and two layers of stones, 100-mm and 50-mm thick, were laid in the center of 4.5-meter wide sections.
• The top layer was a 40-mm thick gravel binding layer.

British Road

• John Macadam (British engineer) designed a scientific road construction method.
• Key to Macadam's method was stone size and compaction.
• Macadam found that well-compacted 250-mm layers of broken angular stone, provided the same strength and stiffness as more expensive methods.
• This produced a cost-effective road construction method.

Highway Development in Iraq

• The first documented road in Iraq dates back to 3500 BC.
• English troops constructed many roads between major Iraqi cities during World War I.
• After the nationalization of Iraqi oil in 1972, many more roads were built.

Modern Roads

• Many Roads currently use Macadam's construction methods.
• The use of bituminous concrete and cement concrete are key developments.
• Advanced and cost-effective construction technologies are employed.
• Development of new equipment speeds road construction.
• Locally sourced materials are often used.
• The increase in travel needs resulted in the rise of alternative transportation like railways and air travel.

Highway Location

• Choosing the location for a highway is crucial:
  • Topography
  • Soil characteristics
  • Environmental factors like noise and air pollution
  • Economic factors
• Different survey methods are used:
  • Ground surveys
  • Remote sensing (aerial photos and GPS)
  • Computer Graphics (combining computer-generated data and analysis)

Principles of Highway Locations

• Highway elements (curvature, grade) must blend for smooth traffic flow and meet design criteria, and safety standards.
• Highways should minimize disruption to historical and archeological sites and land-use activities.
• Highway location occurs in four phases:
  • Office Study of Existing Information
  • Reconnaissance Survey
  • Preliminary Location Survey
  • Final Location Survey

1- Office Study of Existing Information

• This first phase involves examining the area where the road will be constructed.
  • Topography, geology, climate, traffic volumes
  • Land use, zoning patterns
  • Types of wildlife, locations of recreational, historic, archeological sites, and potential pollution
  • Unit costs for construction and trends in agriculture, commerce, and industry

2- Reconnaissance Survey

• This phase identifies several feasible routes using aerial photographs, considering:
  • Terrain and soil conditions
  • Route serviceability to industrial and population areas
  • Transportation facility crossings (rivers, railroads, highways)
  • Route directness

3- Preliminary Location Survey

• During this phase, feasible routes are established, and preliminary vertical and horizontal alignments are determined.
• These alignments will evaluate the economic and environmental feasibility of routes:
  • Economic Evaluation
    • Road user costs
    • Construction costs
    • Maintenance costs
    • Road user benefits
  • Environmental Evaluation
    • Impact on plant, animal, and human communities

Hyperloop Transportation

• This is a high-speed transportation system encased in a low-pressure tube.
• Advantages:
  • Faster travel times
  • No traffic congestion
  • Solar-powered
  • Operates in all weather conditions
  • Pollution-free
  • Lower costs
  • Safer
  • More convenient
  • Earthquake-resistant
• Disadvantages:
  • Turning is challenging
  • Limited passenger space
  • High speeds can cause dizziness
  • A punctured tunnel could create shock waves

Transportation Organizations

• Federal Agencies:
  • U.S. Department of Transportation (US DOT)
  • Federal Aviation Administration (FAA)
  • Federal Highway Administration (FHWA)
  • Federal Railway Administration (FRA)
  • National Highway Traffic Safety Administration (NHTSA)
  • Federal Transit Administration (FTA)
  • Federal Motor Carrier Safety Administration (FMCSA)
• State & Local Agencies:
  • State Department of Transportation (KDOT)
  • Counties (Douglas County Engineer's Office)
  • Cities (Lawrence City Management)
  • Townships

Trade Associations

• Association of American Railroads (AAR)
• American Road and Transportation Builders Association (ARTBA)
• American Public Transit Association (APTA)
• American Bus Association (ABA)
• Asphalt Institute (AI)
• Portland Cement Association (PCA)

Professional Organizations

• American Society of Civil Engineers (ASCE)
• American Association of State Highway and Transportation Officials (AASHTO)
• Institute of Transportation Engineers (ITE)
• Intelligent Transportation System (ITS) America
• Transportation Research Board (TRB)

Explore the fundamentals of highway engineering, including its significance in civil engineering and the evolution of road construction over time. Discover the importance of ancient roads, particularly Roman roads, in shaping transportation history and their lasting impact on modern engineering practices.