Space Standards for Roads in Urban Areas
1977 Edition

IRC 69 Overview - Fundamental Specifications & Tables

1. Road Types & Their Purposes

• Expressways & Arterial Roads: Principal high-capacity routes; spacing ranges under 1.5 km in CBDs to over 8 km on urban outskirts. Typically divided carriageways with limited parking and loading.
• Sub-arterial Roads: Reduced traffic mobility compared to arterials; spacing from 0.5 km in CBDs up to 3-5 km in suburban areas.
• Collector Roads: Channels traffic from local streets; allow full property access with minimal parking constraints.
• Local Roads: Provide direct access to properties with unrestricted parking and pedestrian access.

2. Suggested Right-of-Way Widths (Table 1)

3. Standard Cross-Section Designs

• Refer IRC 69 illustrations (Figures 1-11).
• Include provisions for roadside vegetation, utilities, and drainage.
• Dimensions may be modified based on traffic demand and additional requirements.

flowchart TD
    A[Expressways/Arterial Roads] -->|Spacing| B(<1.5km to 8km+)
    C[Sub-arterial Roads] -->|Spacing| D(0.5km to 5km)
    E[Collector Roads] -->|Function| F(Collect traffic from local roads)
    G[Local Roads] -->|Function| H(Property access)

Synopsis: IRC 69 highlights the functional classification and spatial standards necessary for effective urban traffic regulation and development planning.

Scope and Implementation of IRC 69 - Core Details

1. Road Classification and Roles

• Expressways & Arterial Roads: Primary traffic corridors with spacing from under 1.5 km (CBD) to more than 8 km (urban peripheries).
• Sub-arterial Roads: Secondary routes featuring lower mobility; spaced 0.5 km (CBD) to 3-5 km (suburbs).
• Collector Roads: Gather traffic from local roads; full access permitted.
• Local Roads: Property access roads with low traffic volumes.

2. Prescribed Right-of-Way (Table 1)

3. Cross-Section Recommendations

• Standard cross-sections (Figures 1-11) incorporate space for trees, services, and drainage.
• Adjustments may be made according to traffic volume and urban needs.

flowchart TD
    A[Expressways & Arterial Roads] -->|Traffic Flow| B[Sub-arterial Roads]
    B -->|Lower Mobility| C[Collector Roads]
    C -->|Traffic Collection| D[Local Roads]
    D -->|Property Access| E[Pedestrian/ Parking]

This classification system supports effective traffic management and urban spatial planning.

Detailed Road Categorization (IRC 69)

1. Road Types and Their Functions

• Expressways: High-speed, limited-access routes designed for uninterrupted through traffic.
• Arterial Roads: Important through routes; spacing approximately less than 1.5 km in CBD zones and at least 8 km on urban edges; usually divided highways with restricted parking/loading.
• Sub-arterial Roads: Serve lower mobility requirements than arterials; spacing about 0.5 km in CBD and 3-5 km in suburban regions.
• Collector Roads: Channel traffic from local roads to arterials; full access allowed; restricted parking during peak times.
• Local Roads: Provide direct property access; low traffic with no parking restrictions.

2. Recommended Right-of-Way Widths (Table 1)

3. Cross-Sectional Layouts

• See IRC 69 Figures 1-11 for typical cross-sections.
• Include allowance for trees, utilities, and drainage.
• Adapt widths considering traffic volumes and urban conditions.

graph TD
    A[Expressways] -->|High Speed| B[Arterial Roads]
    B -->|Moderate Speed| C[Sub-arterial Roads]
    C -->|Lower Speed| D[Collector Roads]
    D -->|Access Roads| E[Local Roads]

Note: Proper spacing and widths facilitate efficient traffic flow and urban compatibility.

Functional Roles and Specifications of Urban Streets (IRC 69)

1. Street Category Functions

2. Land Width Standards

3. Cross-Sectional Design Guidelines

• Refer to IRC 69 Figures 1-11 that provide layouts accommodating traffic, vegetation, utilities, and drainage.
• Widths should be flexible based on traffic intensity and urban requirements.

flowchart TD
    A[Local Roads] --> B[Collector Roads]
    B --> C[Sub-arterial Roads]
    C --> D[Arterial Roads]
    D --> E[Expressways]
    style A fill:#f9f,stroke:#333,stroke-width:2px
    style E fill:#bbf,stroke:#333,stroke-width:2px

Summary: The street network hierarchy ensures efficient traffic circulation, accessibility, and land use compatibility.

Spatial Requirements for Urban Road Categories as per IRC 69

Core Data (Table 1: Suggested Land Widths)

Spacing and Function Overview:

• Arterial Roads: Spaced less than 1.5 km in central business districts, expanding to 8 km or more on urban outskirts; usually divided with controlled parking.
• Sub-arterial Roads: Positioned 0.5 km apart in CBDs, extending to 3-5 km in suburban areas; lower mobility than arterials.
• Collector Roads: Link local streets to arterials, allow full access, with some parking restrictions at peak times.
• Local Roads: Primarily serve property access, with unrestricted parking and pedestrian movement.

Design Notes:

• Widths depend on factors like traffic load, land use, and future growth.
• Cross-section designs incorporate roadside trees, utilities, and drainage systems.
• Adjust widths to accommodate additional urban infrastructure needs.

flowchart LR
    Expressways --> Arterial
    Arterial --> Sub-arterial
    Sub-arterial --> Collector
    Collector --> Local

This structured approach promotes efficient traffic distribution and urban land compatibility.

Recommended Right-of-Way Widths According to IRC 69

Highlights:

• Arterial Roads: Located less than 1.5 km apart in CBDs, up to 8 km in outer urban areas; generally divided with limited parking.
• Sub-arterial Roads: Spaced 0.5 km (CBD) to 3-5 km (suburbs); moderate mobility.
• Collector Roads: Collect traffic from local roads; full access with some parking limits.
• Local Roads: Mainly property access with free parking and pedestrian access.

Guidelines for Cross-Sections:

• Include areas for street trees, utilities, and drainage.
• Widths may be increased for additional urban features.

flowchart LR
    A[Expressways] -->|50-60m| B[Arterial Roads]
    B -->|50-60m| C[Sub-arterial Roads]
    C -->|30-40m| D[Collector Roads]
    D -->|20-30m| E[Local Roads]
    E -->|10-20m| F[Property Access]

This data supports effective traffic movement and urban utility accommodation.

IRC 69: Standard Cross-Sectional Layouts and Space Needs for Urban Roads

1. Recommended Land Widths (Table 1)

2. Cross-Section Elements (Clause 7)

• Must include:
  • Traffic lanes (quantity varies with volume)
  • Roadside greenbelts (trees)
  • Utility corridors (water, power, drainage)
  • Side drains for stormwater runoff
• Dimensions may be scaled up for added facilities.
• Should allow for phased development.

3. General Cross-Section Components

• Carriageway: Width based on traffic demand; arterial roads typically have multiple lanes (approx. 7.5 m per lane).
• Footpaths: Minimum width 1.5 to 2.0 m on each side.
• Median: Present on expressways and arterials, widths between 3 to 6 m.
• Shoulders: Usually 1.5 to 2.5 m on both sides for collectors and arterials.

graph LR
A[Road Cross-Section] --> B[Traffic Lanes]
A --> C[Median]
A --> D[Footpaths]
A --> E[Shoulders]
A --> F[Utilities & Drainage]

For detailed cross-section diagrams, refer to IRC 69 Figures 1-11.

IRC 69: Key Points on Access Control and Parking Regulations

1. Access Restrictions by Road Type

• Expressways & Arterial Roads:

  • Full or partial control of entry points.
  • Parking and loading/unloading generally prohibited or strictly regulated.
  • Pedestrian crossings permitted only at designated intersections.

• Sub-arterial Roads:

  • Similar but with less stringent access control than arterials.

• Collector Roads:

  • Unrestricted access to adjacent properties.
  • Parking typically allowed, except during peak periods.

• Local Roads:

  • Open parking and pedestrian movement.
  • Primarily serve property access.

2. Recommended Right-of-Way Widths (Table 1)

3. Parking Regulations Summary

• Expressways and arterial roads restrict parking/loading to maintain flow.
• Collector roads permit parking with some peak-time limitations.
• Local roads have unrestricted parking.

4. Cross-Section Considerations

• Figures 1-11 of IRC 69 provide typical layouts including trees, utilities, and drainage.
• Width adjustments may be required for additional urban amenities.

graph LR
A[Expressways/Arterial Roads] -->|Restricted Parking| B[Access Control]
B --> C[Pedestrian Crossings at Intersections]
D[Collector Roads] -->|Parking Allowed (Except Peak)| E[Full Access]
F[Local Roads] -->|Unrestricted Parking| G[Property Access]

Summary: The standard promotes controlled access and parking restrictions primarily on high-capacity roads to ensure smooth traffic movement, while allowing flexibility on lower-order streets.

Urban Road Planning and Land Use Integration as per IRC 69

Space Standards and Functional Roles

Key Considerations:

• Arterial roads must maintain continuity for traffic efficiency.
• Spacing varies with urban density; closer in city centers, wider in suburbs.
• Cross-sections provide for street planting, utilities, and drainage.
• Widths and layouts adjust to traffic demands and land use types.

Typical Cross-Section Components

• Carriageway width based on traffic levels.
• Pedestrian footpaths.
• Roadside green belts.
• Utility corridors.
• Stormwater drainage.

graph TD
    A[Land Use Zones] --> B[Local Roads]
    B --> C[Collector Roads]
    C --> D[Sub-arterial Roads]
    D --> E[Arterial Roads]
    E --> F[Expressways]

    style A fill:#f9f,stroke:#333,stroke-width:1px
    style F fill:#bbf,stroke:#333,stroke-width:1px

This approach aligns traffic distribution with urban development patterns for sustainable growth.

IRC 69: Key Safety and Environmental Design Considerations

1. Space Allocation by Road Type

2. Traffic Safety Measures

• Maintaining continuity on arterial roads for smooth flow.
• Restricting pedestrian crossings to intersections on arterials to reduce conflict points.
• Limiting parking and loading on expressways and arterials to enhance safety and traffic movement.
• Allowing full access on collector and local roads while balancing safety.

3. Environmental Provisions

• Including roadside tree plantations in cross-sectional designs.
• Allocating space for utilities and stormwater drains.
• Allowing adaptability in cross-section layouts for environmental features.

Cross-Section Design Guidelines

• Must provide:

  • Traffic lanes
  • Pedestrian walkways
  • Tree plantation strips
  • Utility corridors
  • Side drains

• Dimensions may be increased depending on traffic and environmental needs.

flowchart LR
    A[Expressways] -->|50-60m| B(Arterial Roads)
    B -->|50-60m| C(Sub-arterial Roads)
    C -->|30-40m| D(Collector Roads)
    D -->|20-30m| E(Local Roads)
    E -->|10-20m| F[Property Access]

Summary: IRC 69 stresses appropriate right-of-way widths, controlled access on high-capacity roads for safety, and environmentally conscious design elements like tree planting and drainage for sustainable urban roadways.