IRC Code: Manual of Specifications and Standards for Two Laning of Highways with Paved Shoulder (IRC:SP:73-2018)

‍

The expansion and modernization of India’s highway infrastructure are crucial for improving connectivity, reducing travel time, and enhancing road safety. The Indian Roads Congress (IRC) developed the IRC:SP:73-2018, a comprehensive manual for two-lane highways with paved shoulders, ensuring uniform design, construction, and maintenance standards.

‍

This blog explores the key highlights of this IRC Code, covering geometric design, pavement specifications, safety measures, and project execution for public-private partnership (PPP) and engineering-procurement-construction (EPC) models.

‍

‍

Key Features of IRC:SP:73-2018

‍

1. Geometric Design and Roadway Features

The geometric design of highways plays a critical role in ensuring smooth traffic movement and safety. The essential aspects outlined in the manual include:

• Design Speed:
  • Plain/Rolling Terrain: 100 km/h (Ruling), 80 km/h (Minimum)
  • Mountainous Terrain: 60 km/h (Ruling), 40 km/h (Minimum)​.
• Lane Width & Right of Way (ROW):
  • Lane width: 3.5 meters per lane.
  • ROW: Minimum 30 meters, extendable for future expansion​.
• Shoulders:
  • Paved shoulders: 2.5 meters.
  • Earthen shoulders: 1.5 meters (depending on terrain).
• Camber & Crossfall:
  • Crossfall: 2.5% for bituminous surfaces, 2% for concrete.
  • Shoulders have reverse crossfall to prevent waterlogging.

‍

2. Pavement Design and Materials

‍

The durability and load-bearing capacity of highways depend on proper pavement design and high-quality materials. The manual specifies:

• Flexible Pavements:
  • Constructed as per IRC:37 guidelines with a granular sub-base and bituminous layers​.
• Rigid Pavements:
  • Designed per IRC:58 with cement concrete layers.
• Traffic Load Considerations:
  • Pavement thickness is based on cumulative standard axle loads (MSA) over design life.
• Drainage Requirements:
  • Side drains and sub-surface drainage structures to prevent pavement damage.

‍

3. Safety and Traffic Control Measures

‍

Road safety provisions are critical to reducing accidents. The IRC:SP:73-2018 mandates:

• Traffic Signs & Road Markings:
  • Compliance with IRC:67 and IRC:35 for signage and lane markings.
  • Use of retro-reflective materials for better night-time visibility​.
• Roadside Safety Barriers:
  • Placement of crash barriers at curves, embankments, and intersections.
• Pedestrian and Cyclist Safety:
  • Dedicated footpaths and crossing zones in urban sections.
• Work Zone Traffic Management (WTMPs):
  • Guidelines for safe construction zone operations, temporary diversions, and sign placements.

‍

4. Highway Structures and Drainage System

‍

The manual outlines standards for bridges, culverts, and road drainage to prevent structural failures.

• Bridge Width and Load Capacity:
  • Design as per IRC:6 and IRC:112.
  • Minimum 5.5 meters vertical clearance for underpasses​.
• Roadside Drainage:
  • Proper cross-drainage structures for stormwater management.
• Protection Measures for Hill Roads:
  • Retaining walls and reinforced earth structures for landslide prevention.

‍

5. Public-Private Partnership (PPP) & EPC Execution

‍

The PPP model is vital for financing and executing highway projects. The concession agreement includes:

• Concessionaire Responsibilities:
  • Design, construction, operation, and maintenance of the highway​.
  • Preparation of a Quality Assurance Manual (QAM) for material and workmanship compliance.
• Independent Engineer’s Role:
  • Ensuring compliance with IRC and MoRTH specifications.
• Project Management and Timeline Compliance:
  • Stipulated timelines for road completion and defect liability period.

‍

Conclusion

‍

The IRC:SP:73-2018 sets the benchmark for designing two-lane highways with paved shoulders, ensuring better road safety, durability, and efficient project execution. With standardized pavement structures, geometric guidelines, and safety measures, this IRC Code is instrumental in developing high-quality highway infrastructure across India. By following these specifications, road agencies, contractors, and policymakers can enhance connectivity and ensure long-term sustainability of India’s highway network.

‍

RoadVision AI is revolutionizing road infrastructure development and maintenance with its innovative solutions powered by computer vision AI. By leveraging advanced technologies, the platform conducts comprehensive road condition monitoring and traffic surveys, enabling early detection of surface issues like potholes and cracks for timely repairs and enhanced roads. Through traffic congestion analysis, RoadVision AI provides data-driven insights to address traffic congestion challenges and optimize road usage. With a focus on building smarter and more efficient road infrastructure, RoadVision AI ensures full compliance with IRC Codes, helping engineers and stakeholders reduce costs, minimize risks, and improve road safety and transportation efficiency.