Highway Planning and Classification

Highway Planning and Classification

• Highway planning, like all engineering projects, needs development planning. Planning highways is done to achieve specific goals.

Highway Planning Objectives

• Plan a highway network for safe, efficient, and fast movement of people and goods.
• Minimize the overall cost of construction and maintenance of roads.
• Plan for future development and anticipated traffic needs over a specific period.
• Phase road development based on utility, importance, and financial resources.
• Develop a financing system compatible with cost and benefits.

Road Classification Factors

• Materials: Earthen, gravel, murrum, kankar, WBM (Water Bound Macadam), bituminous, and concrete roads.
• Location & Function: National highways, state highways, district roads (major and other), village roads, expressways.
• Traffic Volume: Light, medium, high traffic.
• Economy: Low, medium, high cost roads.
• Traffic Type: Pedestrian ways, cycle tracks, motorways.
• Rigidity: Flexible, rigid roads.
• Topography: Plain area, hilly area roads.

Road Classification Based on Location and Function

• National Highways: Connect national capitals, state capitals, and major port towns. Should be at least two lanes wide with high-class surface finishing.
• State Highways: Connect important towns and cities within a state. Should be two lanes wide, with wide shoulders and good surface finishing.
• District Roads (Major): Connect production and market areas to state or national highways. At least one lane wide with modern surface finishing.
• District Roads (Other): Lower specifications than major district and state highways. Must have proper drainage.
• Village Roads: Used for village travel. Stabilized earth surfaces are common, but metal surfaces are preferable for more useful purposes, and local district boards are responsible for construction and maintenance.
• Expressways: High-class roads for fast-moving vehicles, controlled access and grade separation are key features

Highway Classification by Function

• Mobility: Continuous travel.
• Accessibility: Direct access to abutting property. Some roads serve one or both of these roles.

Highway Classification

• Classified based on the function they serve (functional classification) or the responsible entity (jurisdictional classification).

Highway Classes (Urban/Rural)

• Urban roads comprise highway facilities within urban areas with at least 5000 people.
• Rural areas have different characteristics regarding land use and population density that impact travel patterns.

Functional Classification of Highways

• Urban (principal arterial, minor arterial, collector, local street).
• Rural (principal arterial, minor arterial, collector, major collector, minor collector, local road).

Major Highway Classes

• Arterial: High mobility, low access, long trips.
• Collector: Moderate mobility, moderate access, moderate trip lengths.
• Local: Moderate speed, low mobility, high access, short trips.

Road Patterns in Urban Areas

• Grid Iron: Rectangular or block pattern, easy to set out in straight lines, suitable for flat terrain (also known as rectangular/block pattern).
• Radial: Roads emanate from a central focal area, possibly a business center or a public building. Ring roads can be used for traffic relief.
• Hexagonal: Basic figure is a hexagon, can be modified into triangles, facilitates minimal travel time.